diff --git a/core/modules/layout_builder/css/layout-builder.css b/core/modules/layout_builder/css/layout-builder.css
index 0691f09..45daa82 100644
--- a/core/modules/layout_builder/css/layout-builder.css
+++ b/core/modules/layout_builder/css/layout-builder.css
@@ -40,20 +40,20 @@
   background-image: url(../../../misc/icons/787878/ex.svg);
 }
 
-#drupal-off-canvas  details.layout-selection {
+#drupal-off-canvas details.layout-selection {
   background-color: transparent;
 }
 
-#drupal-off-canvas  details.layout-selection summary {
+#drupal-off-canvas details.layout-selection summary {
   margin-bottom: 1em;
 }
 
-#drupal-off-canvas  details.layout-selection li {
+#drupal-off-canvas details.layout-selection li {
   display: block;
   padding-bottom: 1em;
 }
 
-#drupal-off-canvas  details.layout-selection li a {
+#drupal-off-canvas details.layout-selection li a {
   display: block;
   padding-top: 0.55em;
 }
diff --git a/core/modules/layout_builder/js/layout-builder.es6.js b/core/modules/layout_builder/js/layout-builder.es6.js
index 56a921c..74a5cbb 100644
--- a/core/modules/layout_builder/js/layout-builder.es6.js
+++ b/core/modules/layout_builder/js/layout-builder.es6.js
@@ -1,18 +1,27 @@
-(function ($, Drupal) {
-
-  Drupal.behaviors.layoutBuilder = {
-
-    attach: function (context) {
+(($, { ajax, behaviors }) => {
+  behaviors.layoutBuilder = {
+    attach(context) {
       $(context).find('.layout__region').sortable({
         items: '> .draggable',
         connectWith: '.layout__region',
-        update: function (event, ui) {
-          let data = {
+
+        /**
+         * Updates the layout with the new position of the block.
+         *
+         * @param {jQuery.Event} event
+         *   The jQuery Event object.
+         * @param {Object} ui
+         *   An object containing information about the item being sorted.
+         */
+        update(event, ui) {
+          const data = {
             region_to: $(this).data('region'),
             block_uuid: ui.item.data('layout-block-uuid'),
             delta_to: ui.item.closest('[data-layout-delta]').data('layout-delta'),
-            preceding_block_uuid: ui.item.prev('[data-layout-block-uuid]').data('layout-block-uuid')
+            preceding_block_uuid: ui.item.prev('[data-layout-block-uuid]').data('layout-block-uuid'),
           };
+
+          // @todo What does this condition guard against?
           if (this === ui.item.parent()[0]) {
             if (ui.sender) {
               data.region_from = ui.sender.data('region');
@@ -23,18 +32,13 @@
               data.delta_from = data.delta_to;
             }
 
-            let url = ui.item.closest('[data-layout-update-url]').data('layout-update-url');
-
-            let ajax = Drupal.ajax({
-              url: url,
-              submit: data
-            });
-            ajax.execute();
+            ajax({
+              url: ui.item.closest('[data-layout-update-url]').data('layout-update-url'),
+              submit: data,
+            }).execute();
           }
-        }
+        },
       });
-    }
-
+    },
   };
-
 })(jQuery, Drupal);
diff --git a/core/modules/layout_builder/js/layout-builder.js b/core/modules/layout_builder/js/layout-builder.js
index eca948d..c56b992 100644
--- a/core/modules/layout_builder/js/layout-builder.js
+++ b/core/modules/layout_builder/js/layout-builder.js
@@ -5,14 +5,16 @@
 * @preserve
 **/
 
-(function ($, Drupal) {
-
-  Drupal.behaviors.layoutBuilder = {
+(function ($, _ref) {
+  var ajax = _ref.ajax,
+      behaviors = _ref.behaviors;
 
+  behaviors.layoutBuilder = {
     attach: function attach(context) {
       $(context).find('.layout__region').sortable({
         items: '> .draggable',
         connectWith: '.layout__region',
+
         update: function update(event, ui) {
           var data = {
             region_to: $(this).data('region'),
@@ -20,6 +22,7 @@
             delta_to: ui.item.closest('[data-layout-delta]').data('layout-delta'),
             preceding_block_uuid: ui.item.prev('[data-layout-block-uuid]').data('layout-block-uuid')
           };
+
           if (this === ui.item.parent()[0]) {
             if (ui.sender) {
               data.region_from = ui.sender.data('region');
@@ -29,17 +32,13 @@
               data.delta_from = data.delta_to;
             }
 
-            var url = ui.item.closest('[data-layout-update-url]').data('layout-update-url');
-
-            var ajax = Drupal.ajax({
-              url: url,
+            ajax({
+              url: ui.item.closest('[data-layout-update-url]').data('layout-update-url'),
               submit: data
-            });
-            ajax.execute();
+            }).execute();
           }
         }
       });
     }
-
   };
 })(jQuery, Drupal);
\ No newline at end of file
diff --git a/core/modules/layout_builder/layout_builder.info.yml b/core/modules/layout_builder/layout_builder.info.yml
index d7bedde..7947421 100644
--- a/core/modules/layout_builder/layout_builder.info.yml
+++ b/core/modules/layout_builder/layout_builder.info.yml
@@ -6,4 +6,5 @@ version: VERSION
 core: 8.x
 dependencies:
   - layout_discovery
+  # @todo Remove dependency once https://www.drupal.org/node/2784443 is in.
   - settings_tray
diff --git a/core/modules/layout_builder/layout_builder.module b/core/modules/layout_builder/layout_builder.module
index b9e30a3..eb37353 100644
--- a/core/modules/layout_builder/layout_builder.module
+++ b/core/modules/layout_builder/layout_builder.module
@@ -24,23 +24,6 @@ function layout_builder_help($route_name) {
 }
 
 /**
- * Implements hook_contextual_links_view_alter().
- *
- * Change Configure Blocks into off_canvas links.
- */
-function layout_builder_contextual_links_view_alter(&$element, $items) {
-  // @todo Move this to system_contextual_links_view_alter().
-  // If any items use the off_canvas render, add the corresponding library.
-  foreach ($items as $item) {
-    if (isset($item['localized_options']['attributes']['data-dialog-renderer']) && $item['localized_options']['attributes']['data-dialog-renderer'] === 'off_canvas') {
-      $element['#attached']['library'][] = 'settings_tray/drupal.off_canvas';
-      // After finding one, stop.
-      break;
-    }
-  }
-}
-
-/**
  * Implements hook_form_FORM_ID_alter() for \Drupal\field_ui\Form\EntityViewDisplayEditForm.
  */
 function layout_builder_form_entity_view_display_edit_form_alter(&$form, FormStateInterface $form_state) {
@@ -49,7 +32,7 @@ function layout_builder_form_entity_view_display_edit_form_alter(&$form, FormSta
   $entity_type = \Drupal::entityTypeManager()->getDefinition($display->getTargetEntityTypeId());
 
   // Remove layout_builder__layout both visually and from the #fields handling.
-  // This prevents any interaction with this field. It is manipulated directly
+  // This prevents any interaction with this field. It is rendered directly
   // in layout_builder_entity_view_display_alter().
   unset($form['fields']['layout_builder__layout']);
   unset($form['#fields'][array_search('layout_builder__layout', $form['#fields'])]);
@@ -68,6 +51,7 @@ function layout_builder_form_entity_view_display_edit_form_alter(&$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');
 }
 
diff --git a/core/modules/layout_builder/layout_builder.services.yml b/core/modules/layout_builder/layout_builder.services.yml
index dcb254d..defcfca 100644
--- a/core/modules/layout_builder/layout_builder.services.yml
+++ b/core/modules/layout_builder/layout_builder.services.yml
@@ -9,7 +9,7 @@ services:
     class: Drupal\layout_builder\Access\LayoutSectionAccessCheck
     arguments: ['@entity_type.manager']
     tags:
-      - { name: access_check, applies_to: _has_layout_selection }
+      - { name: access_check, applies_to: _has_layout_section }
   layout_builder.routes:
     class: Drupal\layout_builder\Routing\LayoutBuilderRoutes
     arguments: ['@entity_type.manager']
diff --git a/core/modules/layout_builder/src/Form/ConfigureBlockForm.php b/core/modules/layout_builder/src/Form/ConfigureBlockForm.php
index bb60337..fb5cf93 100644
--- a/core/modules/layout_builder/src/Form/ConfigureBlockForm.php
+++ b/core/modules/layout_builder/src/Form/ConfigureBlockForm.php
@@ -221,7 +221,6 @@ public function buildForm(array $form, FormStateInterface $form_state, $entity_t
     ];
 
     $form['#attached']['library'][] = 'core/drupal.dialog.ajax';
-    $form['#attributes']['id'] = 'dialog-form';
 
     return $form;
   }
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 2ca2248..d870b95 100644
--- a/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
+++ b/core/modules/layout_builder/src/Plugin/Field/FieldType/LayoutSectionItem.php
@@ -33,7 +33,7 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
       ->setLabel(new TranslatableMarkup('Layout'))
       ->setSetting('case_sensitive', FALSE)
       ->setRequired(TRUE);
-    $properties[static::mainPropertyName()] = MapDataDefinition::create('map')
+    $properties['section'] = MapDataDefinition::create('map')
       ->setLabel(new TranslatableMarkup('Layout Section'))
       ->setRequired(FALSE);
 
@@ -58,7 +58,7 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
           'length' => '255',
           'binary' => FALSE,
         ],
-        static::mainPropertyName() => [
+        'section' => [
           'type' => 'blob',
           'size' => 'normal',
           'serialize' => TRUE,
@@ -74,7 +74,7 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
    */
   public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
     $values['layout'] = 'layout_onecol';
-    $values[static::mainPropertyName()] = [];
+    $values['section'] = [];
     return $values;
   }
 
diff --git a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
index 0566132..7a53f52 100644
--- a/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
+++ b/core/modules/layout_builder/src/Routing/LayoutBuilderRoutes.php
@@ -51,7 +51,7 @@ public function getRoutes() {
         ])
         ->addRequirements([
           $entity_type_id => '\d+',
-          '_has_layout_selection' => 'true',
+          '_has_layout_section' => 'true',
         ])
         ->addOptions([
           '_layout_builder' => TRUE,
@@ -71,7 +71,7 @@ public function getRoutes() {
         ])
         ->addRequirements([
           $entity_type_id => '\d+',
-          '_has_layout_selection' => 'true',
+          '_has_layout_section' => 'true',
         ])
         ->addOptions([
           '_layout_builder' => TRUE,
@@ -91,7 +91,7 @@ public function getRoutes() {
         ])
         ->addRequirements([
           $entity_type_id => '\d+',
-          '_has_layout_selection' => 'true',
+          '_has_layout_section' => 'true',
         ])
         ->addOptions([
           '_layout_builder' => TRUE,