diff --git a/.github/workflows/nightly-main.yml b/.github/workflows/nightly-main.yml
index 86029fa9..1faec511 100644
--- a/.github/workflows/nightly-main.yml
+++ b/.github/workflows/nightly-main.yml
@@ -20,9 +20,3 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           gh workflow run ci.yml --ref main
-
-      - name: Execute multi-version tests on 'main'
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          gh workflow run typo3-multi-version-tests.yml --ref main -f force_full_test=true
diff --git a/Tests/Extensions/test_container/Configuration/TCA/Overrides/tt_content.php b/Tests/Extensions/test_container/Configuration/TCA/Overrides/tt_content.php
deleted file mode 100644
index 29caa183..00000000
--- a/Tests/Extensions/test_container/Configuration/TCA/Overrides/tt_content.php
+++ /dev/null
@@ -1,77 +0,0 @@
-<?php
-
-defined('TYPO3') or die();
-
-use B13\Container\Tca\ContainerConfiguration;
-use B13\Container\Tca\Registry;
-use TYPO3\CMS\Core\Utility\GeneralUtility;
-
-// Only register if container extension is loaded
-if (\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::isLoaded('container')) {
-
-    $containerRegistry = GeneralUtility::makeInstance(Registry::class);
-
-    // Register a simple two-column container for testing
-    $containerConfiguration = new ContainerConfiguration(
-        'test_container_2col', // CType
-        'Test Two Columns', // label
-        'Two column container for testing paste-reference functionality', // description
-        [
-            [
-                ['name' => 'Left Column', 'colPos' => 101],
-                ['name' => 'Right Column', 'colPos' => 102],
-            ],
-        ] // grid configuration
-    );
-
-    $containerConfiguration->setIcon('EXT:test_container/Resources/Public/Icons/container-2col.svg');
-    $containerConfiguration->setSaveAndCloseInNewContentElementWizard(false);
-
-    $containerRegistry->configureContainer($containerConfiguration);
-
-    // Register a nested container for advanced testing
-    $nestedContainerConfiguration = new ContainerConfiguration(
-        'test_container_nested', // CType
-        'Test Nested Container', // label
-        'Nested container for testing complex paste-reference scenarios', // description
-        [
-            [
-                ['name' => 'Main Area', 'colPos' => 201],
-            ],
-            [
-                ['name' => 'Sub Left', 'colPos' => 202],
-                ['name' => 'Sub Right', 'colPos' => 203],
-            ],
-        ] // grid configuration
-    );
-
-    $nestedContainerConfiguration->setIcon('EXT:test_container/Resources/Public/Icons/container-nested.svg');
-    $nestedContainerConfiguration->setSaveAndCloseInNewContentElementWizard(false);
-
-    $containerRegistry->configureContainer($nestedContainerConfiguration);
-
-    // Add containers to content element wizard
-    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTcaSelectItem(
-        'tt_content',
-        'CType',
-        [
-            'label' => 'Test Two Columns',
-            'value' => 'test_container_2col',
-            'icon' => 'content-container-columns-2',
-            'group' => 'container',
-            'description' => 'Two column container for testing',
-        ]
-    );
-
-    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTcaSelectItem(
-        'tt_content',
-        'CType',
-        [
-            'label' => 'Test Nested Container',
-            'value' => 'test_container_nested',
-            'icon' => 'content-container-columns-3',
-            'group' => 'container',
-            'description' => 'Nested container for testing',
-        ]
-    );
-}
diff --git a/Tests/Extensions/test_container/Resources/Public/Icons/container-2col.svg b/Tests/Extensions/test_container/Resources/Public/Icons/container-2col.svg
deleted file mode 100644
index 24c6ccbe..00000000
--- a/Tests/Extensions/test_container/Resources/Public/Icons/container-2col.svg
+++ /dev/null
@@ -1,6 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16">
-    <rect x="1" y="2" width="6" height="12" fill="none" stroke="currentColor" stroke-width="1"/>
-    <rect x="9" y="2" width="6" height="12" fill="none" stroke="currentColor" stroke-width="1"/>
-    <text x="4" y="9" font-size="3" text-anchor="middle" fill="currentColor">L</text>
-    <text x="12" y="9" font-size="3" text-anchor="middle" fill="currentColor">R</text>
-</svg>
\ No newline at end of file
diff --git a/Tests/Extensions/test_container/Resources/Public/Icons/container-nested.svg b/Tests/Extensions/test_container/Resources/Public/Icons/container-nested.svg
deleted file mode 100644
index b2ec92f1..00000000
--- a/Tests/Extensions/test_container/Resources/Public/Icons/container-nested.svg
+++ /dev/null
@@ -1,8 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16">
-    <rect x="1" y="1" width="14" height="6" fill="none" stroke="currentColor" stroke-width="1"/>
-    <rect x="1" y="9" width="6" height="6" fill="none" stroke="currentColor" stroke-width="1"/>
-    <rect x="9" y="9" width="6" height="6" fill="none" stroke="currentColor" stroke-width="1"/>
-    <text x="8" y="5" font-size="2" text-anchor="middle" fill="currentColor">MAIN</text>
-    <text x="4" y="12.5" font-size="2" text-anchor="middle" fill="currentColor">L</text>
-    <text x="12" y="12.5" font-size="2" text-anchor="middle" fill="currentColor">R</text>
-</svg>
\ No newline at end of file
diff --git a/Tests/Extensions/test_container/ext_emconf.php b/Tests/Extensions/test_container/ext_emconf.php
deleted file mode 100644
index 67847500..00000000
--- a/Tests/Extensions/test_container/ext_emconf.php
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-/** @var string $_EXTKEY */
-$EM_CONF[$_EXTKEY] = [
-    'title' => 'Test Container Extension',
-    'description' => 'Minimal container extension for testing paste-reference functionality',
-    'category' => 'misc',
-    'author' => 'Test Author',
-    'author_email' => 'test@example.com',
-    'state' => 'stable',
-    'version' => '1.0.0',
-    'constraints' => [
-        'depends' => [
-            'typo3' => '13.0.0-14.99.99',
-            'container' => '3.0.0-3.99.99',
-        ],
-        'conflicts' => [],
-        'suggests' => [],
-    ],
-];
diff --git a/Tests/Extensions/test_container/ext_localconf.php b/Tests/Extensions/test_container/ext_localconf.php
deleted file mode 100644
index f655fb90..00000000
--- a/Tests/Extensions/test_container/ext_localconf.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-defined('TYPO3') or die();
-
-// Register container elements for testing
-if (\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::isLoaded('container')) {
-    // Container registration is done in TCA/Overrides/tt_content.php
-}
diff --git a/Tests/Extensions/test_sitepackage b/Tests/Extensions/test_sitepackage
new file mode 160000
index 00000000..ce9ffff4
--- /dev/null
+++ b/Tests/Extensions/test_sitepackage
@@ -0,0 +1 @@
+Subproject commit ce9ffff440c63da92ee330405626991cfee8835f