diff --git a/packages/themes/block-theme/includes/block-margin.php b/packages/themes/block-theme/includes/block-margin.php
deleted file mode 100644
index 6b85c6b..0000000
--- a/packages/themes/block-theme/includes/block-margin.php
+++ /dev/null
@@ -1,133 +0,0 @@
-<?php
-/**
- * Setup T2 Custom Block Margin v2.
- *
- * @package BlockTheme
- */
-
-declare( strict_types = 1 );
-namespace BlockTheme\BlockMargin;
-
-defined( 'ABSPATH' ) || exit;
-
-// Hooks.
-\add_filter( 't2/custom_block_margin/root_selector', __NAMESPACE__ . '\\do_override_root_selector', 10, 2 );
-\add_filter( 't2/custom_block_margin/last/selectors', __NAMESPACE__ . '\\do_override_last_selectors' );
-\add_filter( 't2/custom_block_margin/config', __NAMESPACE__ . '\\do_override_custom_block_margin_config', 10, 2 );
-\add_filter( 't2/custom_block_margin/default/size_key', fn() => '80' );
-\add_filter( 't2/custom_block_margin/last/size_key', fn() => '80' );
-\add_filter( 'render_block', __NAMESPACE__ . '\\do_add_block_spacing_support_to_additional_containers' );
-
-/**
- * Change the root selector to all contrained containers.
- *
- * @param string  $root_selector Root selector.
- * @param boolean $is_editor Is editor.
- * @return string
- */
-function do_override_root_selector( string $root_selector, bool $is_editor ): string {
-	return $is_editor ? ':is(.block-editor-writing-flow, body)' : 'body';
-}
-
-/**
- * Overide the last selector to include .entry-content blocks only.
- *
- * @return array
- */
-function do_override_last_selectors(): array {
-	return [
-		// Only non-alignfull last child in entry content container.
-		'body .entry-content.is-layout-constrained > :last-child:not(.alignfull)',
-	];
-}
-
-/**
- * Override T2 Custom Block Margin Config.
- *
- * @param array  $config Config.
- * @param string $root_selector Root selector.
- * @return array
- */
-function do_override_custom_block_margin_config( array $config, $root_selector ): array {
-	// Simplify root selector to include only containers supported by Block Spacing API.
-	$config['selector'] = "{$root_selector} :is(
-		.wp-site-blocks,
-		.is-layout-flow,
-		.is-layout-flex.is-vertical,
-		.is-layout-constrained,
-	)";
-
-	$config['gaps'] = [
-		'00' => [
-			'selectors' => [
-				// First child in any container.
-				':first-child',
-
-				// Trailing full size Groups and Covers.
-				'.wp-block-group.alignfull + .wp-block-group.alignfull',
-				'.wp-block-cover.alignfull + .wp-block-cover.alignfull',
-
-				// Spacer blocks.
-				'.wp-block-spacer',
-				'.wp-block-spacer + *',
-				'.wp-block-t2-spacer',
-				'.wp-block-t2-spacer + *',
-			],
-		],
-		'20' => [
-			'selectors' => [],
-		],
-		'30' => [
-			'selectors' => [],
-		],
-		'40' => [
-			'selectors' => [],
-		],
-		'50' => [ // Medium.
-			'selectors' => [
-				// Small block spacing for related blocks, e.g. paragraph + paragraph or heading + paragraph.
-				':is(p, .wp-block-list, .wp-block-heading, .wp-block-post-title, summary) + :is(p, .wp-block-list)',
-			],
-		],
-		'60' => [
-			'selectors' => [],
-		],
-		'70' => [
-			'selectors' => [],
-		],
-		'80' => [ // Default.
-			'selectors' => [],
-		],
-	];
-
-	return $config;
-}
-
-/**
- * Override block rendering and add .is-layout-flow to selected containers to support Block Spacing API.
- *
- * @param string $block_content Block content.
- * @return string
- */
-function do_add_block_spacing_support_to_additional_containers( string $block_content ): string {
-	$containers = [
-		'wp-block-media-text__content',
-		't2-simple-media-text__content-inner',
-		't2-accordion-item__inner-container',
-		't2-factbox__inner-container',
-		't2-infobox__content',
-		't2-faq-item__inner-container',
-	];
-
-	foreach ( $containers as $container ) {
-		if ( \str_contains( $block_content, $container ) ) {
-			$processor = new \WP_HTML_Tag_Processor( $block_content );
-			$processor->next_tag( [ 'class_name' => $container ] );
-			$processor->add_class( 'is-layout-flow' );
-
-			$block_content = $processor->get_updated_html();
-		}
-	}
-
-	return $block_content;
-}
diff --git a/packages/themes/block-theme/t2.json b/packages/themes/block-theme/t2.json
index f9a6542..da1b646 100644
--- a/packages/themes/block-theme/t2.json
+++ b/packages/themes/block-theme/t2.json
@@ -36,6 +36,6 @@
 		"t2/wrap-custom-html-block"
 	],
 	"t2/custom-block-margin": {
-		"version": 2
+		"version": "experimental_v3"
 	}
 }
diff --git a/packages/themes/block-theme/theme.json b/packages/themes/block-theme/theme.json
index aa8685c..204fdb3 100644
--- a/packages/themes/block-theme/theme.json
+++ b/packages/themes/block-theme/theme.json
@@ -40,20 +40,6 @@
 				"12": 1.2,
 				"15": 1.5
 			},
-			"t2/custom-block-margin": {
-				"spacing": {
-					"00": "0",
-					"20": "var(--wp--preset--spacing--20)",
-					"30": "var(--wp--preset--spacing--30)",
-					"40": "var(--wp--preset--spacing--40)",
-					"50": "var(--wp--preset--spacing--50)",
-					"60": "var(--wp--preset--spacing--60)",
-					"70": "var(--wp--preset--spacing--70)",
-					"80": "var(--wp--preset--spacing--80)",
-					"default": "var(--wp--preset--spacing--80)",
-					"last": "var(--wp--preset--spacing--80)"
-				}
-			},
 			"t2/featured-content-layout": {
 				"spacing": {
 					"rowGap": "var(--wp--preset--spacing--50)",