diff --git a/migrations/d7_metatag_defaults.yml b/migrations/d7_metatag_defaults.yml
new file mode 100644
index 0000000..d0d0da6
--- /dev/null
+++ b/migrations/d7_metatag_defaults.yml
@@ -0,0 +1,90 @@
+# A default migration mapping for Metatag-D7 default configuration.
+#
+# @see Drupal\metatag\Plugin\migrate\source\d7\MetatagDefault
+
+id: d7_metatag_defaults
+label: Metatag defaults configuration
+migration_tags:
+  - Drupal 7
+
+source:
+  plugin: d7_metatag_defaults
+  source_module: metatag
+  ignore_map: true
+  constants:
+    langcode: en
+    status: true
+    colon: ':'
+    space: ' '
+    colonspace: ': '
+    underline: '_'
+    doubleunderline: '__'
+    config_prefix: 'metatag.metatag_defaults.'
+
+destination:
+  # @todo Can this work without specifying config_name here?
+  plugin: entity:metatag_defaults
+
+process:
+  # @todo Trying to dynamically assign the config_name value.
+  id:
+    -
+      # Prepend config prefix of "metatag.metatag_defaults." to the instance
+      # name, so "node" becomes "metatag.metatag_defaults.node".
+      plugin: concat
+      source:
+        - 'constants/config_prefix'
+        - instance
+    -
+      # Then replace colons with double-underlines, so
+      # "metatag.metatag_defaults.node:article" becomes
+      # "metatag.metatag_defaults.node__article". Perform this with the
+      # "callback" plugin to avoid needing the migrate_plus module which
+      # provides the "str_replace" plugin.
+      plugin: callback
+      callable: str_replace
+      unpack_source: true
+      source:
+        - 'constants/colon'
+        - 'constants/doubleunderline'
+        - instance
+  
+  # @todo Load the status from the config object, because on D7 the items can be
+  # disabled.
+  status: 'constants/status'
+
+  # Let the langcode be assigned at runtime.
+  # langcode: 'constants/langcode'
+
+  label:
+    -
+      # First add a space after the colon separator, e.g. "node:article" will
+      # become "node: article". Perform this with the "callback" plugin to avoid
+      # needing the migrate_plus module which provides the "str_replace" plugin.
+      plugin: callback
+      callable: str_replace
+      unpack_source: true
+      source:
+        - 'constants/colon'
+        - 'constants/colonspace'
+        - instance
+    -
+      # Then replace underscores in the configuration so that e.g.
+      # "taxonomy_term" is converted to "taxonomy term". Perform this with the
+      # "callback" plugin to avoid needing the migrate_plus module which
+      # provides the "str_replace" plugin.
+      plugin: callback
+      callable: str_replace
+      unpack_source: true
+      source:
+        - 'constants/underline'
+        - 'constants/space'
+        - instance
+    -
+      # Next convert the separate words to ucwords format, e.g. "node: article"
+      # will become "Node: Article".
+      plugin: callback
+      callable: ucwords
+
+  # The values have already been converted to D8+ format, so just save the data.
+  tags: converted_tags
diff --git a/src/Plugin/migrate/process/d7/MetatagEntities.php b/src/Plugin/migrate/MigrateMetatagD7Trait.php
similarity index 94%
copy from src/Plugin/migrate/process/d7/MetatagEntities.php
copy to src/Plugin/migrate/MigrateMetatagD7Trait.php
index f5a1e11..7256267 100644
--- a/src/Plugin/migrate/process/d7/MetatagEntities.php
+++ b/src/Plugin/migrate/MigrateMetatagD7Trait.php
@@ -1,85 +1,13 @@
 <?php
 
-namespace Drupal\metatag\Plugin\migrate\process\d7;
+namespace Drupal\metatag\Plugin\migrate;
 
 use Drupal\Component\Utility\Unicode;
-use Drupal\migrate\MigrateException;
-use Drupal\migrate\MigrateExecutableInterface;
-use Drupal\migrate\ProcessPluginBase;
-use Drupal\migrate\Row;
 
 /**
- * Migrate entity data from Metatag on D7.
- *
- * @MigrateProcessPlugin(
- *   id = "d7_metatag_entities",
- *   handle_multiples = TRUE
- * )
+ * Provides some helper logic for migrating data from Metatag-D7.
  */
-class MetatagEntities extends ProcessPluginBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
-    // If there's no data, there's no need to store anything.
-    if (empty($value)) {
-      return NULL;
-    }
-
-    // Re-shape D7 entries into for D8 entries.
-    $old_tags = unserialize($value, ['allowed_classes' => FALSE]);
-
-    // This is expected to be an array, if it isn't then something went wrong.
-    if (!is_array($old_tags)) {
-      throw new MigrateException('Data from Metatag-D7 was not a serialized array.');
-    }
-
-    $tags_map = $this->tagsMap();
-
-    $metatags = [];
-
-    foreach ($old_tags as $d7_metatag_name => $metatag_value) {
-      // If there's no data for this tag, ignore everything.
-      if (empty($metatag_value)) {
-        continue;
-      }
-
-      // @todo Skip these values for now, maybe some version supported these?
-      if (!is_array($metatag_value) || empty($metatag_value['value'])) {
-        continue;
-      }
-
-      // Convert the D7 meta tag name to the D8 equivalent. If this meta tag
-      // is not recognized, skip it.
-      if (empty($tags_map[$d7_metatag_name])) {
-        continue;
-      }
-      $d8_metatag_name = $tags_map[$d7_metatag_name];
-
-      // Convert the nested arrays to a flat structure.
-      if (is_array($metatag_value['value'])) {
-        // Remove empty values.
-        $metatag_value['value'] = array_filter($metatag_value['value']);
-        // Convert the array into a comma-separated list.
-        $metatag_value = implode(', ', $metatag_value['value']);
-      }
-      else {
-        $metatag_value = $metatag_value['value'];
-      }
-      if (!Unicode::validateUtf8($metatag_value)) {
-        $metatag_value = Unicode::convertToUtf8($metatag_value, 'Windows-1252');
-      }
-
-      // Keep the entire data structure.
-      $metatags[$d8_metatag_name] = $metatag_value;
-    }
-
-    // Sort the meta tags alphabetically to make testing easier.
-    ksort($metatags);
-
-    return serialize($metatags);
-  }
+trait MigrateMetatagD7Trait {
 
   /**
    * Match Metatag-D7 meta tags with their D8 counterparts.
@@ -87,7 +15,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
    * @return array
    *   An array of D7 tags to their D8 counterparts.
    */
-  protected function tagsMap() {
+  protected function tagsMap(): array {
     $map = [
       // From the main Metatag module.
       'abstract' => 'abstract',
@@ -447,4 +375,64 @@ protected function tagsMap() {
     return $map;
   }
 
-}
+  /**
+   * Transform the meta tags from D7 to D8+.
+   *
+   * @param array $old_tags
+   *   The old tags.
+   * @param bool $serialize
+   *   Whether or not to serialize the data prior to return.
+   *
+   * @return string|array
+   *   A serialized array or a straight array, depending on the $serialize
+   *   option.
+   */
+  protected function transformTags(array $old_tags, $serialize = TRUE) {
+    $tags_map = $this->tagsMap();
+
+    $metatags = [];
+
+    foreach ($old_tags as $d7_metatag_name => $metatag_value) {
+      // If there's no data for this tag, ignore everything.
+      if (empty($metatag_value)) {
+        continue;
+      }
+
+      // @todo Skip these values for now, maybe some version supported these?
+      if (!is_array($metatag_value) || empty($metatag_value['value'])) {
+        continue;
+      }
+
+      // Convert the D7 meta tag name to the D8 equivalent. If this meta tag
+      // is not recognized, skip it.
+      if (empty($tags_map[$d7_metatag_name])) {
+        continue;
+      }
+      $new_metatag_name = $tags_map[$d7_metatag_name];
+
+      // Convert the nested arrays to a flat structure.
+      if (is_array($metatag_value['value'])) {
+        // Remove empty values.
+        $metatag_value['value'] = array_filter($metatag_value['value']);
+        // Convert the array into a comma-separated list.
+        $metatag_value = implode(', ', $metatag_value['value']);
+      }
+      else {
+        $metatag_value = $metatag_value['value'];
+      }
+      if (!Unicode::validateUtf8($metatag_value)) {
+        $metatag_value = Unicode::convertToUtf8($metatag_value, 'Windows-1252');
+      }
+
+      // Keep the entire data structure.
+      $metatags[$new_metatag_name] = $metatag_value;
+    }
+
+    // Sort the meta tags alphabetically to make testing easier.
+    // @todo Sort using the correct tag plugin sort order.
+    ksort($metatags);
+
+    return $serialize ? serialize($metatags) : $metatags;
+  }
+
+}
\ No newline at end of file
diff --git a/src/Plugin/migrate/process/d7/MetatagEntities.php b/src/Plugin/migrate/process/d7/MetatagEntities.php
index f5a1e11..1e1f6d7 100644
--- a/src/Plugin/migrate/process/d7/MetatagEntities.php
+++ b/src/Plugin/migrate/process/d7/MetatagEntities.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\metatag\Plugin\migrate\process\d7;
 
-use Drupal\Component\Utility\Unicode;
+use Drupal\metatag\Plugin\migrate\MigrateMetatagD7Trait;
 use Drupal\migrate\MigrateException;
 use Drupal\migrate\MigrateExecutableInterface;
 use Drupal\migrate\ProcessPluginBase;
@@ -18,6 +18,8 @@
  */
 class MetatagEntities extends ProcessPluginBase {
 
+  use MigrateMetatagD7Trait;
+
   /**
    * {@inheritdoc}
    */
@@ -35,416 +37,8 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
       throw new MigrateException('Data from Metatag-D7 was not a serialized array.');
     }
 
-    $tags_map = $this->tagsMap();
-
-    $metatags = [];
-
-    foreach ($old_tags as $d7_metatag_name => $metatag_value) {
-      // If there's no data for this tag, ignore everything.
-      if (empty($metatag_value)) {
-        continue;
-      }
-
-      // @todo Skip these values for now, maybe some version supported these?
-      if (!is_array($metatag_value) || empty($metatag_value['value'])) {
-        continue;
-      }
-
-      // Convert the D7 meta tag name to the D8 equivalent. If this meta tag
-      // is not recognized, skip it.
-      if (empty($tags_map[$d7_metatag_name])) {
-        continue;
-      }
-      $d8_metatag_name = $tags_map[$d7_metatag_name];
-
-      // Convert the nested arrays to a flat structure.
-      if (is_array($metatag_value['value'])) {
-        // Remove empty values.
-        $metatag_value['value'] = array_filter($metatag_value['value']);
-        // Convert the array into a comma-separated list.
-        $metatag_value = implode(', ', $metatag_value['value']);
-      }
-      else {
-        $metatag_value = $metatag_value['value'];
-      }
-      if (!Unicode::validateUtf8($metatag_value)) {
-        $metatag_value = Unicode::convertToUtf8($metatag_value, 'Windows-1252');
-      }
-
-      // Keep the entire data structure.
-      $metatags[$d8_metatag_name] = $metatag_value;
-    }
-
-    // Sort the meta tags alphabetically to make testing easier.
-    ksort($metatags);
-
-    return serialize($metatags);
-  }
-
-  /**
-   * Match Metatag-D7 meta tags with their D8 counterparts.
-   *
-   * @return array
-   *   An array of D7 tags to their D8 counterparts.
-   */
-  protected function tagsMap() {
-    $map = [
-      // From the main Metatag module.
-      'abstract' => 'abstract',
-      'cache-control' => 'cache_control',
-      'canonical' => 'canonical_url',
-      'content-language' => 'content_language',
-      'description' => 'description',
-      'expires' => 'expires',
-      'generator' => 'generator',
-      'geo.placename' => 'geo_placename',
-      'geo.position' => 'geo_position',
-      'geo.region' => 'geo_region',
-      'icbm' => 'icbm',
-      'image_src' => 'image_src',
-      'keywords' => 'keywords',
-      'news_keywords' => 'news_keywords',
-      'next' => 'next',
-      'original-source' => 'original_source',
-      'pragma' => 'pragma',
-      'prev' => 'prev',
-      'rating' => 'rating',
-      'referrer' => 'referrer',
-      'refresh' => 'refresh',
-      'revisit-after' => 'revisit_after',
-      'rights' => 'rights',
-      'robots' => 'robots',
-      'set_cookie' => 'set_cookie',
-      'shortlink' => 'shortlink',
-      'standout' => 'standout',
-      'title' => 'title',
-
-      // From metatag_app_links.metatag.inc:
-      'al:android:app_name' => 'al_android_app_name',
-      'al:android:class' => 'al_android_class',
-      'al:android:package' => 'al_android_package',
-      'al:android:url' => 'al_android_url',
-      'al:ios:app_name' => 'al_ios_app_name',
-      'al:ios:app_store_id' => 'al_ios_app_store_id',
-      'al:ios:url' => 'al_ios_url',
-      'al:ipad:app_name' => 'al_ipad_app_name',
-      'al:ipad:app_store_id' => 'al_ipad_app_store_id',
-      'al:ipad:url' => 'al_ipad_url',
-      'al:iphone:app_name' => 'al_iphone_app_name',
-      'al:iphone:app_store_id' => 'al_iphone_app_store_id',
-      'al:iphone:url' => 'al_iphone_url',
-      'al:web:should_fallback' => 'al_web_should_fallback',
-      'al:web:url' => 'al_web_url',
-      'al:windows:app_id' => 'al_windows_app_id',
-      'al:windows:app_name' => 'al_windows_app_name',
-      'al:windows:url' => 'al_windows_url',
-      'al:windows_phone:app_id' => 'al_windows_phone_app_id',
-      'al:windows_phone:app_name' => 'al_windows_phone_app_name',
-      'al:windows_phone:url' => 'al_windows_phone_url',
-      'al:windows_universal:app_id' => 'al_windows_universal_app_id',
-      'al:windows_universal:app_name' => 'al_windows_universal_app_name',
-      'al:windows_universal:url' => 'al_windows_universal_url',
-
-      // From metatag_dc.metatag.inc:
-      'dcterms.contributor' => 'dcterms_contributor',
-      'dcterms.coverage' => 'dcterms_coverage',
-      'dcterms.creator' => 'dcterms_creator',
-      'dcterms.date' => 'dcterms_date',
-      'dcterms.description' => 'dcterms_description',
-      'dcterms.format' => 'dcterms_format',
-      'dcterms.identifier' => 'dcterms_identifier',
-      'dcterms.language' => 'dcterms_language',
-      'dcterms.publisher' => 'dcterms_publisher',
-      'dcterms.relation' => 'dcterms_relation',
-      'dcterms.rights' => 'dcterms_rights',
-      'dcterms.source' => 'dcterms_source',
-      'dcterms.subject' => 'dcterms_subject',
-      'dcterms.title' => 'dcterms_title',
-      'dcterms.type' => 'dcterms_type',
-
-      // From metatag_dc_advanced.metatag.inc:
-      'dcterms.abstract' => 'dcterms_abstract',
-      'dcterms.accessRights' => 'dcterms_access_rights',
-      'dcterms.accrualMethod' => 'dcterms_accrual_method',
-      'dcterms.accrualPeriodicity' => 'dcterms_accrual_periodicity',
-      'dcterms.accrualPolicy' => 'dcterms_accrual_policy',
-      'dcterms.alternative' => 'dcterms_alternative',
-      'dcterms.audience' => 'dcterms_audience',
-      'dcterms.available' => 'dcterms_available',
-      'dcterms.bibliographicCitation' => 'dcterms_bibliographic_citation',
-      'dcterms.conformsTo' => 'dcterms_conforms_to',
-      'dcterms.created' => 'dcterms_created',
-      'dcterms.dateAccepted' => 'dcterms_date_accepted',
-      'dcterms.dateCopyrighted' => 'dcterms_date_copyrighted',
-      'dcterms.dateSubmitted' => 'dcterms_date_submitted',
-      'dcterms.educationLevel' => 'dcterms_education_level',
-      'dcterms.extent' => 'dcterms_extent',
-      'dcterms.hasFormat' => 'dcterms_has_format',
-      'dcterms.hasPart' => 'dcterms_has_part',
-      'dcterms.hasVersion' => 'dcterms_has_version',
-      'dcterms.instructionalMethod' => 'dcterms_instructional_method',
-      'dcterms.isFormatOf' => 'dcterms_is_format_of',
-      'dcterms.isPartOf' => 'dcterms_is_part_of',
-      'dcterms.isReferencedBy' => 'dcterms_is_referenced_by',
-      'dcterms.isReplacedBy' => 'dcterms_is_replaced_by',
-      'dcterms.isRequiredBy' => 'dcterms_is_required_by',
-      'dcterms.issued' => 'dcterms_issued',
-      'dcterms.isVersionOf' => 'dcterms_is_version_of',
-      'dcterms.license' => 'dcterms_license',
-      'dcterms.mediator' => 'dcterms_mediator',
-      'dcterms.medium' => 'dcterms_medium',
-      'dcterms.modified' => 'dcterms_modified',
-      'dcterms.provenance' => 'dcterms_provenance',
-      'dcterms.references' => 'dcterms_references',
-      'dcterms.replaces' => 'dcterms_replaces',
-      'dcterms.requires' => 'dcterms_requires',
-      'dcterms.rightsHolder' => 'dcterms_rights_holder',
-      'dcterms.spatial' => 'dcterms_spatial',
-      'dcterms.tableOfContents' => 'dcterms_table_of_contents',
-      'dcterms.temporal' => 'dcterms_temporal',
-      'dcterms.valid' => 'dcterms_valid',
-
-      // From metatag_facebook.metatag.inc:
-      'fb:admins' => 'fb_admins',
-      'fb:app_id' => 'fb_app_id',
-      'fb:pages' => 'fb_pages',
-
-      // From metatag_favicons.metatag.inc:
-      'apple-touch-icon' => 'apple_touch_icon',
-      'apple-touch-icon-precomposed' => 'apple_touch_icon_precomposed',
-      'apple-touch-icon-precomposed_114x114' => 'apple_touch_icon_precomposed_114x114',
-      'apple-touch-icon-precomposed_120x120' => 'apple_touch_icon_precomposed_120x120',
-      'apple-touch-icon-precomposed_144x144' => 'apple_touch_icon_precomposed_144x144',
-      'apple-touch-icon-precomposed_152x152' => 'apple_touch_icon_precomposed_152x152',
-      'apple-touch-icon-precomposed_180x180' => 'apple_touch_icon_precomposed_180x180',
-      'apple-touch-icon-precomposed_72x72' => 'apple_touch_icon_precomposed_72x72',
-      'apple-touch-icon-precomposed_76x76' => 'apple_touch_icon_precomposed_76x76',
-      'apple-touch-icon_114x114' => 'apple_touch_icon_114x114',
-      'apple-touch-icon_120x120' => 'apple_touch_icon_120x120',
-      'apple-touch-icon_144x144' => 'apple_touch_icon_144x144',
-      'apple-touch-icon_152x152' => 'apple_touch_icon_152x152',
-      'apple-touch-icon_180x180' => 'apple_touch_icon_180x180',
-      'apple-touch-icon_72x72' => 'apple_touch_icon_72x72',
-      'apple-touch-icon_76x76' => 'apple_touch_icon_76x76',
-      'icon_16x16' => 'icon_16x16',
-      'icon_192x192' => 'icon_192x192',
-      'icon_32x32' => 'icon_32x32',
-      'icon_96x96' => 'icon_96x96',
-      'mask-icon' => 'mask-icon',
-      'shortcut icon' => 'shortcut_icon',
-
-      // From metatag_google_cse.metatag.inc:
-      'audience' => 'audience',
-      'department' => 'department',
-      'doc_status' => 'doc_status',
-      'google_rating' => 'google_rating',
-      'thumbnail' => 'thumbnail',
-
-      // From metatag_google_plus.metatag.inc; not doing these, Google+ closed.
-      'itemtype' => '',
-      'itemprop:name' => '',
-      'itemprop:description' => '',
-      'itemprop:image' => '',
-      'author' => '',
-      'publisher' => '',
-
-      // From metatag_hreflang.metatag.inc:
-      'hreflang_xdefault' => 'hreflang_xdefault',
-      // @todo https://www.drupal.org/project/metatag/issues/3077778
-      // 'hreflang_' . $langcode => 'hreflang_per_language',
-      // From metatag_mobile.metatag.inc:
-      'alternate_handheld' => 'alternate_handheld',
-      'android-app-link-alternative' => 'android_app_link_alternative',
-      'android-manifest' => 'android_manifest',
-      'apple-itunes-app' => 'apple_itunes_app',
-      'apple-mobile-web-app-capable' => 'apple_mobile_web_app_capable',
-      'apple-mobile-web-app-status-bar-style' => 'apple_mobile_web_app_status_bar_style',
-      'apple-mobile-web-app-title' => 'apple_mobile_web_app_title',
-      'application-name' => 'application_name',
-      'cleartype' => 'cleartype',
-      'format-detection' => 'format_detection',
-      'HandheldFriendly' => 'handheldfriendly',
-      'ios-app-link-alternative' => 'ios_app_link_alternative',
-      'MobileOptimized' => 'mobileoptimized',
-      'msapplication-allowDomainApiCalls' => 'msapplication_allowDomainApiCalls',
-      'msapplication-allowDomainMetaTags' => 'msapplication_allowDomainMetaTags',
-      'msapplication-badge' => 'msapplication_badge',
-      'msapplication-config' => 'msapplication_config',
-      'msapplication-navbutton-color' => 'msapplication_navbutton_color',
-      'msapplication-notification' => 'msapplication_notification',
-      'msapplication-square150x150logo' => 'msapplication_square150x150logo',
-      'msapplication-square310x310logo' => 'msapplication_square310x310logo',
-      'msapplication-square70x70logo' => 'msapplication_square70x70logo',
-      'msapplication-starturl' => 'msapplication_starturl',
-      'msapplication-task' => 'msapplication_task',
-      'msapplication-task-separator' => 'msapplication_task_separator',
-      'msapplication-tilecolor' => 'msapplication_tilecolor',
-      'msapplication-tileimage' => 'msapplication_tileimage',
-      'msapplication-tooltip' => 'msapplication_tooltip',
-      'msapplication-wide310x150logo' => 'msapplication_wide310x150logo',
-      'msapplication-window' => 'msapplication_window',
-      'theme-color' => 'theme_color',
-      'viewport' => 'viewport',
-      'x-ua-compatible' => 'x_ua_compatible',
-
-      // From metatag_opengraph.metatag.inc:
-      // https://www.drupal.org/project/metatag/issues/3077782
-      'article:author' => 'article_author',
-      'article:expiration_time' => 'article_expiration_time',
-      'article:modified_time' => 'article_modified_time',
-      'article:published_time' => 'article_published_time',
-      'article:publisher' => 'article_publisher',
-      'article:section' => 'article_section',
-      'article:tag' => 'article_tag',
-      'book:author' => 'book_author',
-      'book:isbn' => 'book_isbn',
-      'book:release_date' => 'book_release_date',
-      'book:tag' => 'book_tag',
-      'og:audio' => 'og_audio',
-      'og:audio:secure_url' => 'og_audio_secure_url',
-      'og:audio:type' => 'og_audio_type',
-      'og:country_name' => 'og_country_name',
-      'og:description' => 'og_description',
-      'og:determiner' => 'og_determiner',
-      'og:email' => 'og_email',
-      'og:fax_number' => 'og_fax_number',
-      'og:image' => 'og_image',
-      // @todo '' => 'og_image_alt',
-      'og:image:height' => 'og_image_height',
-      'og:image:secure_url' => 'og_image_secure_url',
-      'og:image:type' => 'og_image_type',
-      'og:image:url' => 'og_image_url',
-      'og:image:width' => 'og_image_width',
-      'og:latitude' => 'og_latitude',
-      'og:locale' => 'og_locale',
-      'og:locale:alternate' => 'og_locale_alternative',
-      'og:locality' => 'og_locality',
-      'og:longitude' => 'og_longitude',
-      'og:phone_number' => 'og_phone_number',
-      'og:postal_code' => 'og_postal_code',
-      'og:region' => 'og_region',
-      'og:see_also' => 'og_see_also',
-      'og:site_name' => 'og_site_name',
-      'og:street_address' => 'og_street_address',
-      'og:title' => 'og_title',
-      'og:type' => 'og_type',
-      'og:updated_time' => 'og_updated_time',
-      'og:url' => 'og_url',
-      // @todo '' => 'og_video',
-      // https://www.drupal.org/project/metatag/issues/3089445
-      // @todo '' => 'og_video_duration',
-      'og:video:height' => 'og_video_height',
-      'og:video:secure_url' => 'og_video_secure_url',
-      'og:video:type' => 'og_video_type',
-      'og:video:url' => 'og_video_url',
-      'og:video:width' => 'og_video_width',
-      'profile:first_name' => 'profile_first_name',
-      'profile:gender' => 'profile_gender',
-      'profile:last_name' => 'profile_last_name',
-      'profile:username' => 'profile_username',
-      'video:actor' => 'video_actor',
-      'video:actor:role' => 'video_actor_role',
-      'video:director' => 'video_director',
-      // @todo 'video:duration' => '',
-      'video:release_date' => 'video_release_date',
-      'video:series' => 'video_series',
-      'video:tag' => 'video_tag',
-      'video:writer' => 'video_writer',
-
-      // From metatag_opengraph_products.metatag.inc:
-      'product:price:amount' => 'product_price_amount',
-      'product:price:currency' => 'product_price_currency',
-      // Not supported in D7.
-      // @todo '' => 'product_retailer_item_id,
-      // Not yet supported in D9.
-      // @todo 'product:availability' => '',
-      // @todo 'product:brand' => '',
-      // @todo 'product:upc' => '',
-      // @todo 'product:ean' => '',
-      // @todo 'product:isbn' => '',
-      // @todo 'product:plural_title' => '',
-      // @todo 'product:retailer' => '',
-      // @todo 'product:retailer_title' => '',
-      // @todo 'product:retailer_part_no' => '',
-      // @todo 'product:mfr_part_no' => '',
-      // @todo 'product:size' => '',
-      // @todo 'product:product_link' => '',
-      // @todo 'product:category' => '',
-      // @todo 'product:color' => '',
-      // @todo 'product:material' => '',
-      // @todo 'product:pattern' => '',
-      // @todo 'product:shipping_cost:amount' => '',
-      // @todo 'product:shipping_cost:currency' => '',
-      // @todo 'product:weight:value' => '',
-      // @todo 'product:weight:units' => '',
-      // @todo 'product:shipping_weight:value' => '',
-      // @todo 'product:shipping_weight:units' => '',
-      // @todo 'product:expiration_time' => '',
-      // @todo 'product:condition' => '',
-
-      // Pinterest.
-      // @todo '' => 'pinterest_id',
-      // @todo '' => 'pinterest_description',
-      // @todo '' => 'pinterest_nohover',
-      // @todo '' => 'pinterest_url',
-      // @todo '' => 'pinterest_media',
-      // @todo '' => 'pinterest_nopin',
-      // @todo '' => 'pinterest_nosearch',
-
-      // From metatag_twitter_cards.metatag.inc:
-      'twitter:app:country' => 'twitter_cards_app_store_country',
-      'twitter:app:id:googleplay' => 'twitter_cards_app_id_googleplay',
-      'twitter:app:id:ipad' => 'twitter_cards_app_id_ipad',
-      'twitter:app:id:iphone' => 'twitter_cards_app_id_iphone',
-      'twitter:app:name:googleplay' => 'twitter_cards_app_name_googleplay',
-      'twitter:app:name:ipad' => 'twitter_cards_app_name_ipad',
-      'twitter:app:name:iphone' => 'twitter_cards_app_name_iphone',
-      'twitter:app:url:googleplay' => 'twitter_cards_app_url_googleplay',
-      'twitter:app:url:ipad' => 'twitter_cards_app_url_ipad',
-      'twitter:app:url:iphone' => 'twitter_cards_app_url_iphone',
-      'twitter:card' => 'twitter_cards_type',
-      'twitter:creator' => 'twitter_cards_creator',
-      'twitter:creator:id' => 'twitter_cards_creator_id',
-      'twitter:data1' => 'twitter_cards_data1',
-      'twitter:data2' => 'twitter_cards_data2',
-      'twitter:description' => 'twitter_cards_description',
-      'twitter:dnt' => 'twitter_cards_donottrack',
-      'twitter:image' => 'twitter_cards_image',
-      'twitter:image0' => 'twitter_cards_gallery_image0',
-      'twitter:image1' => 'twitter_cards_gallery_image1',
-      'twitter:image2' => 'twitter_cards_gallery_image2',
-      'twitter:image3' => 'twitter_cards_gallery_image3',
-      'twitter:image:alt' => 'twitter_cards_image_alt',
-      'twitter:image:height' => 'twitter_cards_image_height',
-      'twitter:image:width' => 'twitter_cards_image_width',
-      'twitter:label1' => 'twitter_cards_label1',
-      'twitter:label2' => 'twitter_cards_label2',
-      'twitter:player' => 'twitter_cards_player',
-      'twitter:player:height' => 'twitter_cards_player_height',
-      'twitter:player:stream' => 'twitter_cards_player_stream',
-      'twitter:player:stream:content_type' => 'twitter_cards_player_stream_content_type',
-      'twitter:player:width' => 'twitter_cards_player_width',
-      'twitter:site' => 'twitter_cards_site',
-      'twitter:site:id' => 'twitter_cards_site_id',
-      'twitter:title' => 'twitter_cards_title',
-      'twitter:url' => 'twitter_cards_page_url',
-
-      // From metatag_verification.metatag.inc:
-      'baidu-site-verification' => 'baidu',
-      'facebook-domain-verification' => 'facebook_domain_verification',
-      'google-site-verification' => 'google_site_verification',
-      'msvalidate.01' => 'bing',
-      'norton-safeweb-site-verification' => 'norton_safe_web',
-      'p:domain_verify' => 'pinterest',
-      // @todo '' => 'pocket',
-      'yandex-verification' => 'yandex',
-    ];
-
-    // Trigger hook_metatag_migrate_metatagd7_tags_map_alter().
-    // Allow modules to override tags or the entity used for token replacements.
-    \Drupal::service('module_handler')->alter('metatag_migrate_metatagd7_tags_map', $map);
-
-    return $map;
+    // Offload the transformation logic.
+    return $this->transformTags($old_tags, FALSE);
   }
 
 }
diff --git a/src/Plugin/migrate/source/d7/MetatagDefaults.php b/src/Plugin/migrate/source/d7/MetatagDefaults.php
new file mode 100644
index 0000000..bd11a44
--- /dev/null
+++ b/src/Plugin/migrate/source/d7/MetatagDefaults.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace Drupal\metatag\Plugin\migrate\source\d7;
+
+use Drupal\metatag\Plugin\migrate\MigrateMetatagD7Trait;
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Drupal 7 Metatag configuration.
+ *
+ * @MigrateSource(
+ *   id = "d7_metatag_defaults",
+ *   source_module = "metatag"
+ * )
+ */
+class MetatagDefaults extends DrupalSqlBase {
+
+  use MigrateMetatagD7Trait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    return $this->select('metatag_config', 'm')
+      ->fields('m', ['instance', 'config']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fields() {
+    $fields = [
+      'instance' => $this->t('Configuration instance'),
+      'config' => $this->t('Meta tag configuration, stored as either a serialized array or a JSON-encoded string.'),
+    ];
+    return $fields;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIds() {
+    $ids['instance']['type'] = 'string';
+    $ids['config']['type'] = 'string';
+    return $ids;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function prepareRow(Row $row) {
+    parent::prepareRow($row);
+
+    $config = $row->getSourceProperty('config');
+    try {
+      // Use the abstract function to support both Metatag v1 and v2 in one go.
+      $config = metatag_data_decode($config);
+
+      // Transform the meta tags.
+      $config = $this->transformTags($config, FALSE);
+
+      $row->setSourceProperty('converted_tags', $config);
+    }
+    catch (\Exception $e) {
+      // Log an error message about this record.
+      throw new MigrateSkipRowException(sprintf('Unable to unserialize record: %s', (string) $config));
+    }
+  }
+
+}
diff --git a/tests/fixtures/d7_metatag.php b/tests/fixtures/d7_metatag.php
index fc7b2d1..fe703b7 100644
--- a/tests/fixtures/d7_metatag.php
+++ b/tests/fixtures/d7_metatag.php
@@ -9,6 +9,7 @@
 
 $connection = Database::getConnection();
 
+// Primary records for Metatag entity data.
 $connection->schema()->createTable('metatag', [
   'fields' => [
     'entity_type' => [
@@ -136,6 +137,148 @@
   ])
   ->execute();
 
+// Metatag global configuration.
+$connection->schema()->createTable('metatag_config', [
+  'fields' => [
+    'cid' => [
+      'type' => 'serial',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'description' => 'The primary identifier for a metatag configuration set.',
+      'no export' => TRUE,
+    ],
+    'instance' => [
+      'type' => 'varchar',
+      'length' => 255,
+      'not null' => TRUE,
+      'default' => '',
+      'description' => 'The machine-name of the configuration, typically entity-type:bundle.',
+    ],
+    'config' => [
+      'type' => 'blob',
+      'size' => 'big',
+      'not null' => TRUE,
+      'serialize' => TRUE,
+      'description' => 'Serialized data containing the meta tag configuration.',
+      'translatable' => TRUE,
+    ],
+  ],
+  'primary key' => ['cid'],
+  'unique keys' => [
+    'instance' => ['instance'],
+  ],
+  'mysql_character_set' => 'utf8',
+]);
+
+$connection->insert('metatag_config')
+  ->fields(['instance', 'config'])
+  ->values([
+    'instance' => 'global',
+    'config' => serialize([
+      'title' => [
+        'value' => 'I\'m in heaven!',
+      ],
+      'description' => [
+        'value' => 'Mango heaven!',
+      ],
+      'robots' => [
+        'value' => [
+          'nofollow' => 'nofollow',
+          'noindex' => 'noindex',
+        ],
+      ],
+    ]),
+  ],
+  [
+    'instance' => 'node',
+    'config' => serialize([
+      'title' => [
+        'value' => '[node:title]',
+      ],
+      'description' => [
+        'value' => 'The summary is: [node:field_summary]',
+      ],
+      'keywords' => [
+        'value' => 'mango, ',
+      ],
+      'robots' => [
+        'value' => [
+          'follow' => 'follow',
+          'index' => 'index',
+        ],
+      ],
+    ]),
+  ],
+  [
+    'instance' => 'node:article',
+    'config' => serialize([
+      'keywords' => [
+        'value' => 'Alphonso, Julie, Zillate',
+      ],
+      'robots' => [
+        'value' => [
+          'nofollow' => 'nofollow',
+          'noindex' => 'noindex',
+        ],
+      ],
+    ]),
+  ],
+  [
+    'instance' => 'taxonomy_term',
+    'config' => serialize([
+      'title' => [
+        'value' => '[term:name]',
+      ],
+      'description' => [
+        'value' => 'The summary is: [term;description]',
+      ],
+      'keywords' => [
+        'value' => 'mango, ',
+      ],
+      'robots' => [
+        'value' => [
+          'follow' => 'follow',
+          'index' => 'index',
+        ],
+      ],
+    ]),
+  ],
+  [
+    'instance' => 'taxonomy_term:tags',
+    'config' => serialize([
+      'keywords' => [
+        'value' => 'Alphonso, Julie, Zillate',
+      ],
+      'robots' => [
+        'value' => [
+          'nofollow' => 'nofollow',
+          'noindex' => 'noindex',
+        ],
+      ],
+    ]),
+  ],
+  [
+    'instance' => 'user',
+    'config' => serialize([
+      'title' => [
+        'value' => '[user:name]',
+      ],
+      'description' => [
+        'value' => 'The summary is: [user;name]',
+      ],
+      'keywords' => [
+        'value' => 'mango, ',
+      ],
+      'robots' => [
+        'value' => [
+          'follow' => 'follow',
+          'index' => 'index',
+        ],
+      ],
+    ]),
+  ])
+  ->execute();
+
 $connection->insert('node')
   ->fields([
     'nid',
diff --git a/tests/src/Kernel/Migrate/d7/MetatagDefaultsTest.php b/tests/src/Kernel/Migrate/d7/MetatagDefaultsTest.php
new file mode 100644
index 0000000..248e878
--- /dev/null
+++ b/tests/src/Kernel/Migrate/d7/MetatagDefaultsTest.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace Drupal\Tests\metatag\Kernel\Migrate\d7;
+
+use Drupal\metatag\Entity\MetatagDefaults;
+use Drupal\Tests\migrate_drupal\Kernel\d7\MigrateDrupal7TestBase;
+
+/**
+ * Tests Metatag-D7 configuration source plugin.
+ *
+ * @group metatag
+ * @covers \Drupal\metatag\Plugin\migrate\source\d7\MetatagDefaults
+ */
+class MetatagDefaultsTest extends MigrateDrupal7TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    // Core modules.
+    // @see testAvailableConfigEntities
+    // 'comment',
+    // 'content_translation',
+    // 'datetime',
+    // 'filter',
+    // 'image',
+    'language',
+    // 'link',
+    // 'menu_link_content',
+    // 'menu_ui',
+    // 'node',
+    // 'taxonomy',
+    // 'telephone',
+    // 'text',
+
+    // Contrib modules.
+    'token',
+
+    // This module.
+    'metatag',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->loadFixture(__DIR__ . '/../../../../fixtures/d7_metatag.php');
+
+    $this->installConfig(static::$modules);
+    $this->installSchema('system', ['sequences']);
+    $this->installEntitySchema('metatag_defaults');
+
+    // @todo Can any of these be skipped?
+    $this->executeMigrations([
+      'language',
+      'd7_metatag_defaults',
+    ]);
+  }
+
+  /**
+   * Asserts various aspects of a Metatag Defaults config object.
+   *
+   * @param string $id
+   *   The config ID.
+   * @param string $language
+   *   The config language.
+   * @param $label
+   *   The config label.
+   *
+   * @internal
+   */
+  protected function assertEntity(string $id, string $language, string $label): void {
+    $defaults = MetatagDefaults::load($id);
+    dump($defaults);
+    $this->assertSame($id, $defaults->id());
+    // $this->assertSame($language, $defaults->language()->getId());
+    // $this->assertSame($label, $defaults->label());
+  }
+
+  /**
+   * Test Metatag default configuration migration from Drupal 7 to 8.
+   */
+  public function testMetatag() {
+    $this->assertEntity('global', 'en', 'Global');
+    $this->assertEntity('node', 'en', 'Content');
+    $this->assertEntity('node__article', 'en', 'Node: Article');
+    $this->assertEntity('taxonomy_term', 'en', 'Taxonomy Term');
+    $this->assertEntity('taxonomy_term__tags', 'en', 'Taxonomy Term: Tags');
+    $this->assertEntity('user', 'en', 'User');
+    // @todo Load Metatag configuration entities.
+    // @todo Confirm the Metatag configuration entities have the expected data.
+  }
+
+}