diff --git a/assets/stylesheets/_z-index.scss b/assets/stylesheets/_z-index.scss
index b494e9f6fdc50..39e1bb461d46b 100644
--- a/assets/stylesheets/_z-index.scss
+++ b/assets/stylesheets/_z-index.scss
@@ -37,6 +37,9 @@ $z-layers: (
 	// Active pill button
 	".components-button.is-button {:focus or .is-primary}": 1,
 
+	// Reusable blocks UI, needs to be above sibling inserter.
+	".editor-block-list__layout .reusable-block-edit-panel": 7,
+
 	// The draggable element should show up above the entire UI
 	".components-draggable__clone": 1000000000,
 
diff --git a/packages/block-library/src/block/edit-panel/style.scss b/packages/block-library/src/block/edit-panel/style.scss
index ff73c68fee7e3..854cfe03f282f 100644
--- a/packages/block-library/src/block/edit-panel/style.scss
+++ b/packages/block-library/src/block/edit-panel/style.scss
@@ -8,8 +8,10 @@
 	font-size: $default-font-size;
 	position: relative;
 	top: -$block-padding;
-	margin: 0 (-$block-padding) (-$block-padding) (-$block-padding);
+	margin: 0 (-$block-padding);
 	padding: $grid-size $block-padding;
+	position: relative;
+	z-index: z-index(".editor-block-list__layout .reusable-block-edit-panel");
 
 	// Show a smaller padding when nested.
 	.editor-block-list__layout & {
diff --git a/packages/block-library/src/columns/editor.scss b/packages/block-library/src/columns/editor.scss
index ebe614483c4a5..a96a6dcf8c1ea 100644
--- a/packages/block-library/src/columns/editor.scss
+++ b/packages/block-library/src/columns/editor.scss
@@ -25,15 +25,6 @@
 	}
 }
 
-// This block has flex container children. Flex container margins do not collapse: https://www.w3.org/TR/css-flexbox-1/#flex-containers.
-// Therefore, let's at least not add any additional margins here.
-// The goal is for the editor to look more like the front-end.
-.editor-block-list__layout .editor-block-list__block[data-type="core/columns"] > .editor-block-list__block-edit,
-.editor-block-list__layout .editor-block-list__block[data-type="core/column"] > .editor-block-list__block-edit {
-	margin-top: 0;
-	margin-bottom: 0;
-}
-
 .wp-block-columns {
 	display: block;
 
@@ -55,8 +46,13 @@
 			// The Column block is a child of the Columns block and is mostly a passthrough container.
 			// Therefore it shouldn't add additional paddings and margins, so we reset these, and compensate for margins.
 			// @todo In the future, if a passthrough feature lands, it would be good to apply these rules to such an element in a more generic way.
-			margin-top: -$block-padding;
-			margin-bottom: -$block-padding;
+			margin-top: -$block-padding - $block-padding;
+			margin-bottom: -$block-padding - $block-padding;
+
+			> .editor-block-list__block-edit {
+				margin-top: 0;
+				margin-bottom: 0;
+			}
 
 			// On mobile, only a single column is shown, so match adjacent block paddings.
 			padding-left: 0;
@@ -130,3 +126,13 @@
 		}
 	}
 }
+
+// In absence of making the individual columns resizable, we prevent them from being clickable.
+// This makes them less fiddly. This will be revisited as the interface is refined.
+.wp-block-columns [data-type="core/column"] {
+	pointer-events: none;
+}
+
+:not(.components-disabled) > .wp-block-columns > .editor-inner-blocks > .editor-block-list__layout > [data-type="core/column"] > .editor-block-list__block-edit > .editor-inner-blocks {
+	pointer-events: all;
+}
diff --git a/packages/components/src/disabled/style.scss b/packages/components/src/disabled/style.scss
index 8ca29bb801e15..77e0dab63a0b8 100644
--- a/packages/components/src/disabled/style.scss
+++ b/packages/components/src/disabled/style.scss
@@ -10,4 +10,9 @@
 		bottom: 0;
 		left: 0;
 	}
+
+	// Also make nested blocks unselectable.
+	* {
+		pointer-events: none;
+	}
 }
diff --git a/packages/editor/src/components/block-list/style.scss b/packages/editor/src/components/block-list/style.scss
index c66a202741175..28632c0eda60a 100644
--- a/packages/editor/src/components/block-list/style.scss
+++ b/packages/editor/src/components/block-list/style.scss
@@ -57,14 +57,9 @@
 		margin-right: -$block-padding;
 	}
 
-	// Adjust the spacing of the appender to match text blocks.
-	.editor-default-block-appender > .editor-default-block-appender__content {
-		margin-top: $block-padding * 2 + $block-spacing;
-	}
-
 	// Space every block, and the default appender, using margins.
 	// This allows margins to collapse, which gives a better representation of how it looks on the frontend.
-	> .editor-default-block-appender__content,
+	.editor-default-block-appender > .editor-default-block-appender__content,
 	> .editor-block-list__block > .editor-block-list__block-edit,
 	> .editor-block-list__layout > .editor-block-list__block > .editor-block-list__block-edit {
 		margin-top: $block-padding * 2 + $block-spacing;