diff --git a/core/modules/layout_builder/layout_builder.links.contextual.yml b/core/modules/layout_builder/layout_builder.links.contextual.yml
index 67952a1f18..bcf2a9cf06 100644
--- a/core/modules/layout_builder/layout_builder.links.contextual.yml
+++ b/core/modules/layout_builder/layout_builder.links.contextual.yml
@@ -1,6 +1,6 @@
-layout_builder_block_configure:
+layout_builder_block_update:
   title: 'Configure'
-  route_name: 'layout_builder.configure_block'
+  route_name: 'layout_builder.update_block'
   group: 'layout_builder_block'
   options:
     attributes:
diff --git a/core/modules/layout_builder/layout_builder.module b/core/modules/layout_builder/layout_builder.module
index e8d8a1116a..74367cd728 100644
--- a/core/modules/layout_builder/layout_builder.module
+++ b/core/modules/layout_builder/layout_builder.module
@@ -6,6 +6,7 @@
  */
 
 use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
@@ -23,6 +24,18 @@ function layout_builder_help($route_name) {
   }
 }
 
+/**
+ * Implements hook_entity_type_alter().
+ */
+function layout_builder_entity_type_alter(array &$entity_types) {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+  foreach ($entity_types as $entity_type) {
+    if ($entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasLinkTemplate('canonical') && $entity_type->hasViewBuilderClass()) {
+      $entity_type->setLinkTemplate('layout-builder', $entity_type->getLinkTemplate('canonical') . '/layout');
+    }
+  }
+}
+
 /**
  * Implements hook_form_FORM_ID_alter() for \Drupal\field_ui\Form\EntityViewDisplayEditForm.
  */
@@ -53,21 +66,22 @@ function layout_builder_form_entity_view_display_edit_form_alter(&$form, FormSta
     '#default_value' => $display->getThirdPartySetting('layout_builder', 'allow_custom', FALSE),
   ];
 
-  // The submit handler should run before the entity is saved by the form.
-  array_unshift($form['actions']['submit']['#submit'], 'layout_builder_form_entity_view_display_edit_submit');
+  $form['#entity_builders'][] = 'layout_builder_form_entity_view_display_edit_entity_builder';
 }
 
 /**
- * Form submission handler for layout options on the entity view display form.
+ * Entity builder for layout options on the entity view display form.
  *
  * @see layout_builder_form_entity_view_display_edit_form_alter()
  */
-function layout_builder_form_entity_view_display_edit_submit(&$form, FormStateInterface $form_state) {
-  /** @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display */
-  $display = $form_state->getFormObject()->getEntity();
+function layout_builder_form_entity_view_display_edit_entity_builder($entity_type_id, EntityViewDisplayInterface $display, &$form, FormStateInterface &$form_state) {
+  // Only proceed once the form has been submitted.
+  if (!$form_state->isSubmitted()) {
+    return;
+  }
 
-  $original_value = $display->getThirdPartySetting('layout_builder', 'allow_custom', FALSE);
-  $allow_custom = $form_state->getValue(['layout', 'allow_custom'], FALSE);
+  $original_value = (bool) $display->getThirdPartySetting('layout_builder', 'allow_custom', FALSE);
+  $allow_custom = (bool) $form_state->getValue(['layout', 'allow_custom'], FALSE);
 
   // Only continue if the value has changed.
   if ($original_value !== $allow_custom) {
diff --git a/core/modules/layout_builder/layout_builder.routing.yml b/core/modules/layout_builder/layout_builder.routing.yml
index 27a234a7be..8fe952afbe 100644
--- a/core/modules/layout_builder/layout_builder.routing.yml
+++ b/core/modules/layout_builder/layout_builder.routing.yml
@@ -70,7 +70,7 @@ layout_builder.choose_block:
 layout_builder.add_block:
   path: '/layout_builder/add/block/{entity_type_id}/{entity}/{delta}/{region}/{plugin_id}'
   defaults:
-    _form: '\Drupal\layout_builder\Form\ConfigureBlockForm'
+    _form: '\Drupal\layout_builder\Form\AddBlockForm'
   requirements:
     _permission: 'configure any layout'
   options:
@@ -80,10 +80,10 @@ layout_builder.add_block:
         type: entity:{entity_type_id}
         layout_builder_tempstore: TRUE
 
-layout_builder.configure_block:
-  path: '/layout_builder/configure/block/{entity_type_id}/{entity}/{delta}/{region}/{uuid}'
+layout_builder.update_block:
+  path: '/layout_builder/update/block/{entity_type_id}/{entity}/{delta}/{region}/{uuid}'
   defaults:
-    _form: '\Drupal\layout_builder\Form\ConfigureBlockForm'
+    _form: '\Drupal\layout_builder\Form\UpdateBlockForm'
   requirements:
     _permission: 'configure any layout'
   options:
diff --git a/core/modules/layout_builder/layout_builder.services.yml b/core/modules/layout_builder/layout_builder.services.yml
index a717a020a7..575dbc75ad 100644
--- a/core/modules/layout_builder/layout_builder.services.yml
+++ b/core/modules/layout_builder/layout_builder.services.yml
@@ -12,7 +12,7 @@ services:
       - { name: access_check, applies_to: _has_layout_section }
   layout_builder.routes:
     class: Drupal\layout_builder\Routing\LayoutBuilderRoutes
-    arguments: ['@entity_type.manager']
+    arguments: ['@entity_type.manager', '@entity_field.manager']
   layout_builder.route_enhancer:
     class: Drupal\layout_builder\Routing\LayoutBuilderRouteEnhancer
     arguments: ['@entity_type.manager']
diff --git a/core/modules/layout_builder/src/Controller/AddSectionController.php b/core/modules/layout_builder/src/Controller/AddSectionController.php
index 5dcf2ef208..5e1f3536aa 100644
--- a/core/modules/layout_builder/src/Controller/AddSectionController.php
+++ b/core/modules/layout_builder/src/Controller/AddSectionController.php
@@ -83,7 +83,7 @@ public function build(EntityInterface $entity, $delta, $plugin_id) {
       return $this->rebuildAndClose($entity);
     }
     else {
-      $url = Url::fromRoute("entity.{$entity->getEntityTypeId()}.layout", [$entity->getEntityTypeId() => $entity->id()]);
+      $url = $entity->toUrl('layout-builder');
       return new RedirectResponse($url->setAbsolute()->toString());
     }
   }
diff --git a/core/modules/layout_builder/src/Controller/LayoutBuilderController.php b/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
index 13f1582944..f121814461 100644
--- a/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
+++ b/core/modules/layout_builder/src/Controller/LayoutBuilderController.php
@@ -10,7 +10,7 @@
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\Url;
 use Drupal\layout_builder\LayoutSectionBuilder;
-use Drupal\layout_builder\LayoutSectionItemInterface;
+use Drupal\layout_builder\Field\LayoutSectionItemInterface;
 use Drupal\layout_builder\LayoutTempstoreRepositoryInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
@@ -111,7 +111,7 @@ public function layout(EntityInterface $entity) {
 
     $output = [];
     $count = 0;
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface $item */
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $item */
     foreach ($entity->layout_builder__layout as $item) {
       $output[] = $this->buildAddSectionLink($entity_type_id, $entity_id, $count);
       $output[] = $this->buildAdministrativeSection($item, $entity, $count);
@@ -169,7 +169,7 @@ protected function buildAddSectionLink($entity_type_id, $entity_id, $delta) {
   /**
    * Builds the render array for the layout section while editing.
    *
-   * @param \Drupal\layout_builder\LayoutSectionItemInterface $item
+   * @param \Drupal\layout_builder\Field\LayoutSectionItemInterface $item
    *   The layout section item.
    * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity.
diff --git a/core/modules/layout_builder/src/Controller/MoveBlockController.php b/core/modules/layout_builder/src/Controller/MoveBlockController.php
index e1be964bad..800223eef6 100644
--- a/core/modules/layout_builder/src/Controller/MoveBlockController.php
+++ b/core/modules/layout_builder/src/Controller/MoveBlockController.php
@@ -59,14 +59,24 @@ public static function create(ContainerInterface $container) {
    *
    * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity.
-   * @param \Symfony\Component\HttpFoundation\Request $request
-   *   The request.
+   * @param int $delta_from
+   *   The delta of the original section.
+   * @param int $delta_to
+   *   The delta of the destination section.
+   * @param string $region_from
+   *   The original region for this block.
+   * @param string $region_to
+   *   The new region for this block.
+   * @param string $block_uuid
+   *   The UUID for this block.
+   * @param string|null $preceding_block_uuid
+   *   (optional) If provided, the UUID of the block to insert this block after.
    *
    * @return \Drupal\Core\Ajax\AjaxResponse
    *   An AJAX response.
    */
-  public function build(EntityInterface $entity, Request $request, $delta_from, $delta_to, $region_from, $region_to, $block_uuid, $preceding_block_uuid = NULL) {
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
+  public function build(EntityInterface $entity, $delta_from, $delta_to, $region_from, $region_to, $block_uuid, $preceding_block_uuid = NULL) {
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
     $field = $entity->layout_builder__layout->get($delta_from);
     $values = $field->section;
 
@@ -74,9 +84,10 @@ public function build(EntityInterface $entity, Request $request, $delta_from, $d
     unset($values[$region_from][$block_uuid]);
     $field->section = array_filter($values);
 
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
-    $field = $entity->layout_builder__layout->get($delta_to);
-    $values = $field->section;
+    if ($delta_from !== $delta_to) {
+      $field = $entity->layout_builder__layout->get($delta_to);
+      $values = $field->section;
+    }
 
     if (isset($preceding_block_uuid)) {
       if (!isset($values[$region_to])) {
@@ -85,7 +96,7 @@ public function build(EntityInterface $entity, Request $request, $delta_from, $d
 
       $slice_id = array_search($preceding_block_uuid, array_keys($values[$region_to]));
       if ($slice_id === FALSE) {
-        throw new \InvalidArgumentException('Invalid preceeding block UUID');
+        throw new \InvalidArgumentException('Invalid preceding block UUID');
       }
 
       $before = array_slice($values[$region_to], 0, $slice_id + 1);
@@ -93,9 +104,7 @@ public function build(EntityInterface $entity, Request $request, $delta_from, $d
       $values[$region_to] = array_merge($before, [$block_uuid => $configuration], $after);
     }
     else {
-      if (empty($values[$region_to])) {
-        $values[$region_to] = [];
-      }
+      $values += [$region_to => []];
       $values[$region_to] = array_merge([$block_uuid => $configuration], $values[$region_to]);
     }
     $field->section = array_filter($values);
diff --git a/core/modules/layout_builder/src/LayoutSectionItemInterface.php b/core/modules/layout_builder/src/Field/LayoutSectionItemInterface.php
similarity index 50%
rename from core/modules/layout_builder/src/LayoutSectionItemInterface.php
rename to core/modules/layout_builder/src/Field/LayoutSectionItemInterface.php
index 48e081a821..c2288608b0 100644
--- a/core/modules/layout_builder/src/LayoutSectionItemInterface.php
+++ b/core/modules/layout_builder/src/Field/LayoutSectionItemInterface.php
@@ -1,12 +1,17 @@
 <?php
 
-namespace Drupal\layout_builder;
+namespace Drupal\layout_builder\Field;
 
 use Drupal\Core\Field\FieldItemInterface;
 
 /**
  * Defines an interface for the layout section field item.
  *
+ * @internal
+ *   Layout Builder is currently experimental and should only be leveraged by
+ *   experimental modules and development releases of contributed modules.
+ *   See https://www.drupal.org/core/experimental for more information.
+ *
  * @property string layout
  * @property array[] layout_settings
  * @property array[] section
diff --git a/core/modules/layout_builder/src/Field/LayoutSectionItemList.php b/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
index 3d31fa2c75..933ed6eb97 100644
--- a/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
+++ b/core/modules/layout_builder/src/Field/LayoutSectionItemList.php
@@ -7,6 +7,8 @@
 /**
  * Defines a item list class for layout section fields.
  *
+ * @internal
+ *
  * @see \Drupal\layout_builder\Plugin\Field\FieldType\LayoutSectionItem
  */
 class LayoutSectionItemList extends FieldItemList implements LayoutSectionItemListInterface {
diff --git a/core/modules/layout_builder/src/Field/LayoutSectionItemListInterface.php b/core/modules/layout_builder/src/Field/LayoutSectionItemListInterface.php
index 0a604d7ea7..81839d1774 100644
--- a/core/modules/layout_builder/src/Field/LayoutSectionItemListInterface.php
+++ b/core/modules/layout_builder/src/Field/LayoutSectionItemListInterface.php
@@ -7,6 +7,11 @@
 /**
  * Defines a item list class for layout section fields.
  *
+ * @internal
+ *   Layout Builder is currently experimental and should only be leveraged by
+ *   experimental modules and development releases of contributed modules.
+ *   See https://www.drupal.org/core/experimental for more information.
+ *
  * @see \Drupal\layout_builder\Plugin\Field\FieldType\LayoutSectionItem
  */
 interface LayoutSectionItemListInterface extends FieldItemListInterface {
@@ -14,7 +19,7 @@
   /**
    * {@inheritdoc}
    *
-   * @return \Drupal\layout_builder\LayoutSectionItemInterface|null
+   * @return \Drupal\layout_builder\Field\LayoutSectionItemInterface|null
    *   The layout section item, if it exists.
    */
   public function get($index);
diff --git a/core/modules/layout_builder/src/Form/AddBlockForm.php b/core/modules/layout_builder/src/Form/AddBlockForm.php
new file mode 100644
index 0000000000..e55106cd57
--- /dev/null
+++ b/core/modules/layout_builder/src/Form/AddBlockForm.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Drupal\layout_builder\Form;
+
+/**
+ * Provides a form to add a block.
+ *
+ * @internal
+ */
+class AddBlockForm extends ConfigureBlockFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'layout_builder_add_block';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function submitLabel() {
+    return $this->t('Add Block');
+  }
+
+}
diff --git a/core/modules/layout_builder/src/Form/ConfigureBlockForm.php b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
similarity index 85%
rename from core/modules/layout_builder/src/Form/ConfigureBlockForm.php
rename to core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
index 1144a73e6d..a91e35478b 100644
--- a/core/modules/layout_builder/src/Form/ConfigureBlockForm.php
+++ b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
@@ -21,11 +21,11 @@
 use Symfony\Component\HttpFoundation\RequestStack;
 
 /**
- * Provides a form to configure a block.
+ * Provides a base form for configuring a block.
  *
  * @internal
  */
-class ConfigureBlockForm extends FormBase {
+abstract class ConfigureBlockFormBase extends FormBase {
 
   use ContextAwarePluginAssignmentTrait;
   use LayoutRebuildFormTrait;
@@ -94,7 +94,7 @@ class ConfigureBlockForm extends FormBase {
   protected $entity;
 
   /**
-   * Constructs a new ConfigureBlockForm.
+   * Constructs a new block form.
    *
    * @param \Drupal\layout_builder\LayoutTempstoreRepositoryInterface $layout_tempstore_repository
    *   The layout tempstore repository.
@@ -136,13 +136,6 @@ public static function create(ContainerInterface $container) {
     );
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function getFormId() {
-    return 'layout_builder_configure_block';
-  }
-
   /**
    * Prepares the block plugin based on the block ID.
    *
@@ -163,26 +156,35 @@ protected function prepareBlock($block_id, array $configuration) {
   }
 
   /**
-   * {@inheritdoc}
+   * Builds the form for the block.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity being configured.
+   * @param int $delta
+   *   The delta of the section.
+   * @param string $region
+   *   The region of the block.
+   * @param string|null $plugin_id
+   *   The plugin ID of the block to add.
+   * @param array $configuration
+   *   (optional) The array of configuration for the block.
+   *
+   * @return array
+   *   The form array.
    */
-  public function buildForm(array $form, FormStateInterface $form_state, EntityInterface $entity = NULL, $delta = NULL, $region = NULL, $plugin_id = NULL, $uuid = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, EntityInterface $entity = NULL, $delta = NULL, $region = NULL, $plugin_id = NULL, array $configuration = []) {
     $this->entity = $entity;
     $this->delta = $delta;
     $this->region = $region;
-
-    $configuration = [];
-    if ($uuid) {
-      /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
-      $field = $this->entity->layout_builder__layout->get($this->delta);
-      $plugin_id = $field->section[$region][$uuid]['block']['id'];
-      $configuration = $field->section[$region][$uuid]['block'];
-    }
     $this->block = $this->prepareBlock($plugin_id, $configuration);
 
     $form_state->setTemporaryValue('gathered_contexts', $this->contextRepository->getAvailableContexts());
 
-    // Some Block Plugins rely on the block_theme value to load theme settings.
-    // @see \Drupal\system\Plugin\Block\SystemBrandingBlock::blockForm().
+    // @todo Remove once https://www.drupal.org/node/2268787 is resolved.
     $form_state->set('block_theme', $this->config('system.theme')->get('default'));
 
     $form['#tree'] = TRUE;
@@ -192,7 +194,7 @@ public function buildForm(array $form, FormStateInterface $form_state, EntityInt
 
     $form['actions']['submit'] = [
       '#type' => 'submit',
-      '#value' => $uuid ? $this->t('Update') : $this->t('Add Block'),
+      '#value' => $this->submitLabel(),
       '#button_type' => 'primary',
     ];
     if ($this->isAjax()) {
@@ -202,6 +204,14 @@ public function buildForm(array $form, FormStateInterface $form_state, EntityInt
     return $form;
   }
 
+  /**
+   * Returns the label for the submit button.
+   *
+   * @return string
+   *   Submit label.
+   */
+  abstract protected function submitLabel();
+
   /**
    * {@inheritdoc}
    */
@@ -225,14 +235,14 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
 
     $configuration = $this->block->getConfiguration();
 
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
     $field = $this->entity->layout_builder__layout->get($this->delta);
     $section = $field->section;
     $section[$this->region][$configuration['uuid']]['block'] = $configuration;
     $field->section = $section;
 
     $this->layoutTempstoreRepository->set($this->entity);
-    $form_state->setRedirect("entity.{$this->entity->getEntityTypeId()}.layout", [$this->entity->getEntityTypeId() => $this->entity->id()]);
+    $form_state->setRedirectUrl($this->entity->toUrl('layout-builder'));
   }
 
   /**
diff --git a/core/modules/layout_builder/src/Form/ConfigureSectionForm.php b/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
index abc1f8c2bb..ddf1c96040 100644
--- a/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
+++ b/core/modules/layout_builder/src/Form/ConfigureSectionForm.php
@@ -127,7 +127,7 @@ public function buildForm(array $form, FormStateInterface $form_state, EntityInt
 
     $configuration = [];
     if ($this->isUpdate) {
-      /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
+      /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
       $field = $this->entity->layout_builder__layout->get($this->delta);
       $plugin_id = $field->layout;
       $configuration = $field->layout_settings;
@@ -186,7 +186,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     }
 
     $this->layoutTempstoreRepository->set($this->entity);
-    $form_state->setRedirect("entity.{$this->entity->getEntityTypeId()}.layout", [$this->entity->getEntityTypeId() => $this->entity->id()]);
+    $form_state->setRedirectUrl($this->entity->toUrl('layout-builder'));
   }
 
   /**
diff --git a/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php b/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
index b1765977ba..6214ea364b 100644
--- a/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
+++ b/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
@@ -73,7 +73,7 @@ public static function create(ContainerInterface $container) {
    * {@inheritdoc}
    */
   public function getCancelUrl() {
-    return Url::fromRoute("entity.{$this->entity->getEntityTypeId()}.layout", [$this->entity->getEntityTypeId() => $this->entity->id()]);
+    return $this->entity->toUrl('layout-builder');
   }
 
   /**
diff --git a/core/modules/layout_builder/src/Form/RemoveBlockForm.php b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
index 8772de2602..0fccbb8bb9 100644
--- a/core/modules/layout_builder/src/Form/RemoveBlockForm.php
+++ b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
@@ -60,7 +60,7 @@ public function buildForm(array $form, FormStateInterface $form_state, EntityInt
    * {@inheritdoc}
    */
   protected function handleEntity(EntityInterface $entity, FormStateInterface $form_state) {
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface $field */
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
     $field = $entity->layout_builder__layout->get($this->delta);
     $values = $field->section;
     unset($values[$this->region][$this->uuid]);
diff --git a/core/modules/layout_builder/src/Form/UpdateBlockForm.php b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
new file mode 100644
index 0000000000..df9369841f
--- /dev/null
+++ b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Drupal\layout_builder\Form;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Provides a form to update a block.
+ *
+ * @internal
+ */
+class UpdateBlockForm extends ConfigureBlockFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'layout_builder_update_block';
+  }
+
+  /**
+   * Builds the block form.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity being configured.
+   * @param int $delta
+   *   The delta of the section.
+   * @param string $region
+   *   The region of the block.
+   * @param string $uuid
+   *   The UUID of the block being updated.
+   *
+   * @return array
+   *   The form array.
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, EntityInterface $entity = NULL, $delta = NULL, $region = NULL, $uuid = NULL) {
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
+    $field = $entity->layout_builder__layout->get($delta);
+    if (empty($field->section[$region][$uuid]['block'])) {
+      throw new \InvalidArgumentException('Invalid UUID specified');
+    }
+
+    $plugin_id = $field->section[$region][$uuid]['block']['id'];
+    $configuration = $field->section[$region][$uuid]['block'];
+
+    return parent::buildForm($form, $form_state, $entity, $delta, $region, $plugin_id, $configuration);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function submitLabel() {
+    return $this->t('Update');
+  }
+
+}
diff --git a/core/modules/layout_builder/src/LayoutSectionBuilder.php b/core/modules/layout_builder/src/LayoutSectionBuilder.php
index fdd6b365fc..1682974f11 100644
--- a/core/modules/layout_builder/src/LayoutSectionBuilder.php
+++ b/core/modules/layout_builder/src/LayoutSectionBuilder.php
@@ -15,6 +15,8 @@
 
 /**
  * Builds the UI for layout sections.
+ *
+ * @internal
  */
 class LayoutSectionBuilder {
 
diff --git a/core/modules/layout_builder/src/LayoutTempstoreRepository.php b/core/modules/layout_builder/src/LayoutTempstoreRepository.php
index 652e9c76d9..87baa1331c 100644
--- a/core/modules/layout_builder/src/LayoutTempstoreRepository.php
+++ b/core/modules/layout_builder/src/LayoutTempstoreRepository.php
@@ -9,6 +9,8 @@
 
 /**
  * Provides a mechanism for loading layouts from tempstore.
+ *
+ * @internal
  */
 class LayoutTempstoreRepository implements LayoutTempstoreRepositoryInterface {
 
@@ -43,13 +45,14 @@ public function __construct(SharedTempStoreFactory $temp_store_factory, EntityTy
    * {@inheritdoc}
    */
   public function get(EntityInterface $entity) {
-    list($collection, $id) = $this->generateTempstoreId($entity);
-    $tempstore = $this->tempStoreFactory->get($collection)->get($id);
+    $id = $this->generateTempstoreId($entity);
+    $tempstore = $this->getTempstore($entity)->get($id);
     if (!empty($tempstore['entity'])) {
+      $entity_type_id = $entity->getEntityTypeId();
       $entity = $tempstore['entity'];
 
       if (!($entity instanceof EntityInterface)) {
-        throw new \UnexpectedValueException(sprintf('The entry for collection "%s" and ID "%s" is not a valid entity', $collection, $id));
+        throw new \UnexpectedValueException(sprintf('The entry with entity type "%s" and ID "%s" is not a valid entity', $entity_type_id, $id));
       }
     }
     return $entity;
@@ -67,8 +70,8 @@ public function getFromId($entity_type_id, $entity_id) {
    * {@inheritdoc}
    */
   public function set(EntityInterface $entity) {
-    list($collection, $id) = $this->generateTempstoreId($entity);
-    $this->tempStoreFactory->get($collection)->set($id, ['entity' => $entity]);
+    $id = $this->generateTempstoreId($entity);
+    $this->getTempstore($entity)->set($id, ['entity' => $entity]);
   }
 
   /**
@@ -76,27 +79,40 @@ public function set(EntityInterface $entity) {
    */
   public function delete(EntityInterface $entity) {
     if ($this->get($entity)) {
-      list($collection, $id) = $this->generateTempstoreId($entity);
-      $this->tempStoreFactory->get($collection)->delete($id);
+      $id = $this->generateTempstoreId($entity);
+      $this->getTempstore($entity)->delete($id);
     }
   }
 
   /**
-   * Generates a collection and ID for putting an entity in tempstore.
+   * Generates an ID for putting an entity in tempstore.
    *
    * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity being stored.
    *
-   * @return array
-   *   An array containing the collection name and the tempstore ID.
+   * @return string
+   *   The tempstore ID.
    */
   protected function generateTempstoreId(EntityInterface $entity) {
-    $collection = $entity->getEntityTypeId() . '.layout_builder__layout';
     $id = "{$entity->id()}.{$entity->language()->getId()}";
     if ($entity instanceof RevisionableInterface) {
       $id .= '.' . $entity->getRevisionId();
     }
-    return [$collection, $id];
+    return $id;
+  }
+
+  /**
+   * Gets the shared tempstore.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity being stored.
+   *
+   * @return \Drupal\user\SharedTempStore
+   *   The tempstore.
+   */
+  protected function getTempstore(EntityInterface $entity) {
+    $collection = $entity->getEntityTypeId() . '.layout_builder__layout';
+    return $this->tempStoreFactory->get($collection);
   }
 
 }
diff --git a/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php b/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
index af6f382d35..ffce1c3008 100644
--- a/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
+++ b/core/modules/layout_builder/src/LayoutTempstoreRepositoryInterface.php
@@ -6,6 +6,11 @@
 
 /**
  * Provides an interface for loading layouts from tempstore.
+ *
+ * @internal
+ *   Layout Builder is currently experimental and should only be leveraged by
+ *   experimental modules and development releases of contributed modules.
+ *   See https://www.drupal.org/core/experimental for more information.
  */
 interface LayoutTempstoreRepositoryInterface {
 
diff --git a/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php b/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
index 7b3a1762a1..02a1ea14df 100644
--- a/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
+++ b/core/modules/layout_builder/src/Plugin/Derivative/LayoutBuilderLocalTaskDeriver.php
@@ -5,7 +5,6 @@
 use Drupal\Component\Plugin\Derivative\DeriverBase;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\layout_builder\Plugin\Menu\LayoutBuilderLocalTask;
@@ -51,8 +50,8 @@ public static function create(ContainerInterface $container, $base_plugin_id) {
    */
   public function getDerivativeDefinitions($base_plugin_definition) {
     foreach (array_keys($this->getEntityTypes()) as $entity_type_id) {
-      $this->derivatives["entity.$entity_type_id.layout"] = $base_plugin_definition + [
-        'route_name' => "entity.$entity_type_id.layout",
+      $this->derivatives["entity.$entity_type_id.layout_builder"] = $base_plugin_definition + [
+        'route_name' => "entity.$entity_type_id.layout_builder",
         'weight' => 15,
         'title' => $this->t('Layout'),
         'base_route' => "entity.$entity_type_id.canonical",
@@ -62,14 +61,14 @@ public function getDerivativeDefinitions($base_plugin_definition) {
       $this->derivatives["entity.$entity_type_id.save_layout"] = $base_plugin_definition + [
         'route_name' => "entity.$entity_type_id.save_layout",
         'title' => $this->t('Save Layout'),
-        'parent_id' => "layout_builder_ui:entity.$entity_type_id.layout",
+        'parent_id' => "layout_builder_ui:entity.$entity_type_id.layout_builder",
         'entity_type_id' => $entity_type_id,
         'class' => LayoutBuilderLocalTask::class,
       ];
       $this->derivatives["entity.$entity_type_id.cancel_layout"] = $base_plugin_definition + [
         'route_name' => "entity.$entity_type_id.cancel_layout",
         'title' => $this->t('Cancel Layout'),
-        'parent_id' => "layout_builder_ui:entity.$entity_type_id.layout",
+        'parent_id' => "layout_builder_ui:entity.$entity_type_id.layout_builder",
         'entity_type_id' => $entity_type_id,
         'class' => LayoutBuilderLocalTask::class,
         'weight' => 5,
@@ -87,7 +86,7 @@ public function getDerivativeDefinitions($base_plugin_definition) {
    */
   protected function getEntityTypes() {
     return array_filter($this->entityTypeManager->getDefinitions(), function (EntityTypeInterface $entity_type) {
-      return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasLinkTemplate('canonical') && $entity_type->hasViewBuilderClass();
+      return $entity_type->hasLinkTemplate('layout-builder');
     });
   }
 
diff --git a/core/modules/layout_builder/src/Plugin/Field/FieldFormatter/LayoutSectionFormatter.php b/core/modules/layout_builder/src/Plugin/Field/FieldFormatter/LayoutSectionFormatter.php
index bbc8b2f3c6..4951d01c4b 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldFormatter/LayoutSectionFormatter.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldFormatter/LayoutSectionFormatter.php
@@ -12,6 +12,8 @@
 /**
  * Plugin implementation of the 'layout_section' formatter.
  *
+ * @internal
+ *
  * @FieldFormatter(
  *   id = "layout_section",
  *   label = @Translation("Layout Section"),
@@ -76,7 +78,7 @@ public static function create(ContainerInterface $container, array $configuratio
   public function viewElements(FieldItemListInterface $items, $langcode) {
     $elements = [];
 
-    /** @var \Drupal\layout_builder\LayoutSectionItemInterface[] $items */
+    /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface[] $items */
     foreach ($items as $delta => $item) {
       $elements[$delta] = $this->builder->buildSection($item->layout, $item->layout_settings, $item->section);
     }
diff --git a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
index 136073b11f..490aee48d3 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
@@ -8,11 +8,13 @@
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\Core\TypedData\MapDataDefinition;
-use Drupal\layout_builder\LayoutSectionItemInterface;
+use Drupal\layout_builder\Field\LayoutSectionItemInterface;
 
 /**
  * Plugin implementation of the 'layout_section' field type.
  *
+ * @internal
+ *
  * @FieldType(
  *   id = "layout_section",
  *   label = @Translation("Layout Section"),
diff --git a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
index d4dfecbf04..896384f5cd 100644
--- a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
+++ b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\layout_builder\Routing;
 
+use Drupal\Core\Entity\EntityFieldManagerInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
@@ -21,14 +22,24 @@ class LayoutBuilderRoutes {
    */
   protected $entityTypeManager;
 
+  /**
+   * The entity field manager.
+   *
+   * @var \Drupal\Core\Entity\EntityFieldManagerInterface
+   */
+  protected $entityFieldManager;
+
   /**
    * Constructs a new LayoutBuilderRoutes.
    *
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager.
+   * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
+   *   The entity field manager.
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $entity_field_manager) {
     $this->entityTypeManager = $entity_type_manager;
+    $this->entityFieldManager = $entity_field_manager;
   }
 
   /**
@@ -41,8 +52,10 @@ public function getRoutes() {
     $routes = [];
 
     foreach ($this->getEntityTypes() as $entity_type_id => $entity_type) {
-      $template = $entity_type->getLinkTemplate('canonical');
-      $route = (new Route("$template/layout"))
+      $integer_id = $this->hasIntegerId($entity_type);
+
+      $template = $entity_type->getLinkTemplate('layout-builder');
+      $route = (new Route($template))
         ->setDefaults([
           '_controller' => '\Drupal\layout_builder\Controller\LayoutBuilderController::layout',
           '_title_callback' => '\Drupal\layout_builder\Controller\LayoutBuilderController::title',
@@ -50,7 +63,6 @@ public function getRoutes() {
           'entity_type_id' => $entity_type_id,
         ])
         ->addRequirements([
-          $entity_type_id => '\d+',
           '_has_layout_section' => 'true',
         ])
         ->addOptions([
@@ -62,16 +74,18 @@ public function getRoutes() {
             ],
           ],
         ]);
-      $routes["entity.$entity_type_id.layout"] = $route;
+      if ($integer_id) {
+        $route->setRequirement($entity_type_id, '\d+');
+      }
+      $routes["entity.$entity_type_id.layout_builder"] = $route;
 
-      $route = (new Route("$template/layout/save"))
+      $route = (new Route("$template/save"))
         ->setDefaults([
           '_controller' => '\Drupal\layout_builder\Controller\LayoutBuilderController::saveLayout',
           'entity' => NULL,
           'entity_type_id' => $entity_type_id,
         ])
         ->addRequirements([
-          $entity_type_id => '\d+',
           '_has_layout_section' => 'true',
         ])
         ->addOptions([
@@ -83,16 +97,18 @@ public function getRoutes() {
             ],
           ],
         ]);
+      if ($integer_id) {
+        $route->setRequirement($entity_type_id, '\d+');
+      }
       $routes["entity.$entity_type_id.save_layout"] = $route;
 
-      $route = (new Route("$template/layout/cancel"))
+      $route = (new Route("$template/cancel"))
         ->setDefaults([
           '_controller' => '\Drupal\layout_builder\Controller\LayoutBuilderController::cancelLayout',
           'entity' => NULL,
           'entity_type_id' => $entity_type_id,
         ])
         ->addRequirements([
-          $entity_type_id => '\d+',
           '_has_layout_section' => 'true',
         ])
         ->addOptions([
@@ -104,11 +120,28 @@ public function getRoutes() {
             ],
           ],
         ]);
+      if ($integer_id) {
+        $route->setRequirement($entity_type_id, '\d+');
+      }
       $routes["entity.$entity_type_id.cancel_layout"] = $route;
     }
     return $routes;
   }
 
+  /**
+   * Determines if this entity type's ID is stored as an integer.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   An entity type.
+   *
+   * @return bool
+   *   TRUE if this entity type's ID key is always an integer, FALSE otherwise.
+   */
+  protected function hasIntegerId(EntityTypeInterface $entity_type) {
+    $field_storage_definitions = $this->entityFieldManager->getFieldStorageDefinitions($entity_type->id());
+    return $field_storage_definitions[$entity_type->getKey('id')]->getType() === 'integer';
+  }
+
   /**
    * Returns an array of relevant entity types.
    *
@@ -117,7 +150,7 @@ public function getRoutes() {
    */
   protected function getEntityTypes() {
     return array_filter($this->entityTypeManager->getDefinitions(), function (EntityTypeInterface $entity_type) {
-      return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasLinkTemplate('canonical') && $entity_type->hasViewBuilderClass();
+      return $entity_type->hasLinkTemplate('layout-builder');
     });
   }
 
diff --git a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
index 0e30d14d04..61e481c7c7 100644
--- a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
@@ -162,12 +162,12 @@ public function providerTestLayoutSectionFormatter() {
    * @dataProvider providerTestLayoutSectionFormatter
    */
   public function testLayoutSectionFormatter($layout_data, $expected_selector, $expected_content, $expected_cache_contexts, $expected_cache_tags, $expected_dynamic_cache) {
-    $this->createSectionNode($layout_data);
+    $node = $this->createSectionNode($layout_data);
 
-    $this->drupalGet('node/1');
+    $this->drupalGet($node->toUrl('canonical'));
     $this->assertLayoutSection($expected_selector, $expected_content, $expected_cache_contexts, $expected_cache_tags, $expected_dynamic_cache);
 
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($node->toUrl('layout-builder'));
     $this->assertLayoutSection($expected_selector, $expected_content, $expected_cache_contexts, $expected_cache_tags, 'UNCACHEABLE');
   }
 
@@ -175,7 +175,7 @@ public function testLayoutSectionFormatter($layout_data, $expected_selector, $ex
    * Tests the access checking of the section formatter.
    */
   public function testLayoutSectionFormatterAccess() {
-    $this->createSectionNode([
+    $node = $this->createSectionNode([
       [
         'layout' => 'layout_onecol',
         'section' => [
@@ -193,14 +193,14 @@ public function testLayoutSectionFormatterAccess() {
     // Restrict access to the block.
     $this->container->get('state')->set('test_block_access', FALSE);
 
-    $this->drupalGet('node/1');
+    $this->drupalGet($node->toUrl('canonical'));
     $this->assertLayoutSection('.layout--onecol', NULL, '', '', 'UNCACHEABLE');
     // Ensure the block was not rendered.
     $this->assertSession()->pageTextNotContains('Hello test world');
 
     // Grant access to the block, and ensure it was rendered.
     $this->container->get('state')->set('test_block_access', TRUE);
-    $this->drupalGet('node/1');
+    $this->drupalGet($node->toUrl('canonical'));
     $this->assertLayoutSection('.layout--onecol', 'Hello test world', '', '', 'UNCACHEABLE');
   }
 
@@ -256,9 +256,9 @@ public function testMultilingualLayoutSectionFormatter() {
     ]);
     $entity->save();
 
-    $this->drupalGet('node/1');
+    $this->drupalGet($entity->toUrl('canonical'));
     $this->assertLayoutSection('.layout--onecol', 'Powered by');
-    $this->drupalGet('es/node/1');
+    $this->drupalGet($entity->toUrl('canonical')->setOption('prefix', 'es/'));
     $this->assertLayoutSection('.layout--twocol', ['foo text', 'bar text']);
   }
 
@@ -267,9 +267,9 @@ public function testMultilingualLayoutSectionFormatter() {
    */
   public function testLayoutPageTitle() {
     $this->drupalPlaceBlock('page_title_block');
-    $this->createSectionNode([]);
+    $node = $this->createSectionNode([]);
 
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($node->toUrl('layout-builder'));
     $this->assertSession()->titleEquals('Edit layout for The node title | Drupal');
     $this->assertEquals('Edit layout for The node title', $this->cssSelect('h1.page-title')[0]->getText());
   }
@@ -278,7 +278,7 @@ public function testLayoutPageTitle() {
    * Tests that no Layout link shows without a section field.
    */
   public function testLayoutUrlNoSectionField() {
-    $this->createNode([
+    $node = $this->createNode([
       'type' => 'bundle_without_section_field',
       'title' => 'The node title',
       'body' => [
@@ -287,7 +287,8 @@ public function testLayoutUrlNoSectionField() {
         ],
       ],
     ]);
-    $this->drupalGet('node/1/layout');
+    $node->save();
+    $this->drupalGet($node->toUrl('layout-builder'));
     $this->assertSession()->statusCodeEquals(403);
   }
 
diff --git a/core/modules/layout_builder/tests/src/FunctionalJavascript/LayoutBuilderTest.php b/core/modules/layout_builder/tests/src/FunctionalJavascript/LayoutBuilderTest.php
index ecfff5680e..1bf83bca47 100644
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/LayoutBuilderTest.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/LayoutBuilderTest.php
@@ -4,6 +4,7 @@
 
 use Drupal\block_content\Entity\BlockContent;
 use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\Url;
 use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
 use Drupal\Tests\contextual\FunctionalJavascript\ContextualLinkClickTrait;
 
@@ -28,6 +29,13 @@ class LayoutBuilderTest extends JavascriptTestBase {
     'layout_test',
   ];
 
+  /**
+   * The node to customize with Layout Builder.
+   *
+   * @var \Drupal\node\NodeInterface
+   */
+  protected $node;
+
   /**
    * {@inheritdoc}
    */
@@ -54,7 +62,7 @@ protected function setUp() {
     ])->save();
 
     $this->createContentType(['type' => 'bundle_with_section_field']);
-    $this->createNode([
+    $this->node = $this->createNode([
       'type' => 'bundle_with_section_field',
       'title' => 'The node title',
       'body' => [
@@ -80,12 +88,12 @@ protected function setUp() {
   /**
    * Tests the Layout Builder UI.
    */
-  public function test() {
+  public function testLayoutBuilderUi() {
     $assert_session = $this->assertSession();
     $page = $this->getSession()->getPage();
 
     // Ensure the block is not displayed initially.
-    $this->drupalGet('node/1');
+    $this->drupalGet($this->node->toUrl('canonical'));
     $assert_session->pageTextNotContains('Powered by Drupal');
 
     // Enter the layout editing mode.
@@ -124,28 +132,28 @@ public function test() {
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->elementNotExists('css', '#drupal-off-canvas');
 
-    $assert_session->addressEquals('node/1/layout');
+    $assert_session->addressEquals($this->node->toUrl('layout-builder'));
     $assert_session->pageTextContains('Powered by Drupal');
     $assert_session->pageTextContains('This is the label');
     $this->assertPageNotReloaded();
 
     // Until the layout is saved, the new block is not visible on the node page.
-    $this->drupalGet('node/1');
+    $this->drupalGet($this->node->toUrl('canonical'));
     $assert_session->pageTextNotContains('Powered by Drupal');
 
     // When returning to the layout edit mode, the new block is visible.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $assert_session->pageTextContains('Powered by Drupal');
 
     // Save the layout, and the new block is visible.
     $this->clickLink('Save Layout');
-    $assert_session->addressEquals('node/1');
+    $assert_session->addressEquals($this->node->toUrl('canonical'));
     $assert_session->pageTextContains('Powered by Drupal');
     $assert_session->pageTextContains('This is the label');
     $assert_session->elementExists('css', '.layout');
 
     // Drag one block from one region to another.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $this->markCurrentPage();
 
     $this->clickLink('Add Section');
@@ -165,7 +173,7 @@ public function test() {
     $this->assertPageNotReloaded();
 
     // Ensure the drag persisted after reload.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $assert_session->elementExists('css', '.layout__region--second .block-system-powered-by-block');
     $assert_session->elementTextContains('css', '.layout__region--second', 'Powered by Drupal');
 
@@ -175,7 +183,7 @@ public function test() {
     $assert_session->elementTextContains('css', '.layout__region--second', 'Powered by Drupal');
 
     // Configure a block.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $this->markCurrentPage();
 
     $this->clickContextualLink('.block-system-powered-by-block', 'Configure');
@@ -187,7 +195,7 @@ public function test() {
     $assert_session->assertWaitOnAjaxRequest();
     $assert_session->elementNotExists('css', '#drupal-off-canvas');
 
-    $assert_session->addressEquals('node/1/layout');
+    $assert_session->addressEquals($this->node->toUrl('layout-builder'));
     $assert_session->pageTextContains('Powered by Drupal');
     $assert_session->pageTextContains('This is the new label');
     $assert_session->pageTextNotContains('This is the label');
@@ -203,14 +211,14 @@ public function test() {
 
     $assert_session->pageTextNotContains('Powered by Drupal');
     $assert_session->linkExists('Add Block');
-    $assert_session->addressEquals('node/1/layout');
+    $assert_session->addressEquals($this->node->toUrl('layout-builder'));
     $this->assertPageNotReloaded();
 
     $this->clickLink('Save Layout');
     $assert_session->elementExists('css', '.layout');
 
     // Test deriver-based blocks.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $this->markCurrentPage();
 
     $this->clickLink('Add Block');
@@ -251,7 +259,7 @@ public function testConfigurableLayouts() {
     $assert_session = $this->assertSession();
     $page = $this->getSession()->getPage();
 
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $this->markCurrentPage();
 
     $this->clickLink('Add Section');
@@ -295,21 +303,27 @@ public function testLayoutNoDialog() {
     $page = $this->getSession()->getPage();
 
     // Set up a layout with one section.
-    $this->drupalGet('node/1/layout');
+    $this->drupalGet($this->node->toUrl('layout-builder'));
     $this->clickLink('Add Section');
     $assert_session->assertWaitOnAjaxRequest();
     $this->clickLink('One column');
     $assert_session->assertWaitOnAjaxRequest();
 
     // Test bypassing the Off Canvas dialog by visiting the URL directly.
-    $this->drupalGet('layout_builder/add/block/node/1/0/content/system_powered_by_block');
+    $this->drupalGet(Url::fromRoute('layout_builder.add_block', [
+      'entity_type_id' => 'node',
+      'entity' => 1,
+      'delta' => 0,
+      'region' => 'content',
+      'plugin_id' => 'system_powered_by_block',
+    ]));
     $assert_session->elementNotExists('css', '#drupal-off-canvas');
     $page->fillField('settings[label]', 'The block label');
     $page->fillField('settings[label_display]', TRUE);
     $page->pressButton('Add Block');
     $assert_session->assertWaitOnAjaxRequest();
 
-    $assert_session->addressEquals('node/1/layout');
+    $assert_session->addressEquals($this->node->toUrl('layout-builder'));
     $assert_session->pageTextContains('Powered by Drupal');
     $assert_session->pageTextContains('The block label');
   }
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemTest.php b/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemTest.php
index 76d7ea74c0..0e13471c15 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemTest.php
@@ -5,7 +5,7 @@
 use Drupal\Core\Field\FieldItemInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\entity_test\Entity\EntityTest;
-use Drupal\layout_builder\LayoutSectionItemInterface;
+use Drupal\layout_builder\Field\LayoutSectionItemInterface;
 use Drupal\layout_builder\Field\LayoutSectionItemListInterface;
 use Drupal\Tests\field\Kernel\FieldKernelTestBase;
 
diff --git a/core/modules/layout_builder/tests/src/Unit/LayoutTempstoreRepositoryTest.php b/core/modules/layout_builder/tests/src/Unit/LayoutTempstoreRepositoryTest.php
index faef394d4f..a652d4a56d 100644
--- a/core/modules/layout_builder/tests/src/Unit/LayoutTempstoreRepositoryTest.php
+++ b/core/modules/layout_builder/tests/src/Unit/LayoutTempstoreRepositoryTest.php
@@ -126,7 +126,7 @@ public function testGetInvalidEntity() {
     $entity->getEntityTypeId()->willReturn('the_entity_type_id');
     $entity->id()->willReturn('the_entity_id');
 
-    $this->setExpectedException(\UnexpectedValueException::class, 'The entry for collection "the_entity_type_id.layout_builder__layout" and ID "the_entity_id.en" is not a valid entity');
+    $this->setExpectedException(\UnexpectedValueException::class, 'The entry with entity type "the_entity_type_id" and ID "the_entity_id.en" is not a valid entity');
     $repository->get($entity->reveal());
   }