diff --git a/pxtblocks/builtins/loops.ts b/pxtblocks/builtins/loops.ts
index 1b70cfdd6a0a..6eb52bd4b7c1 100644
--- a/pxtblocks/builtins/loops.ts
+++ b/pxtblocks/builtins/loops.ts
@@ -2,6 +2,7 @@
 
 import * as Blockly from "blockly";
 import { installBuiltinHelpInfo, setBuiltinHelpInfo, setHelpResources } from "../help";
+import { setDuplicateOnDrag } from "../plugins/duplicateOnDrag";
 
 export function initLoops() {
     const msg = Blockly.Msg;
@@ -104,6 +105,7 @@ export function initLoops() {
             }
         }
     };
+    setDuplicateOnDrag(pxtControlsForId, "VAR");
 
     // controls_simple_for
     const controlsSimpleForId = "controls_simple_for";
@@ -313,6 +315,7 @@ export function initLoops() {
                 );
             }
         };
+        setDuplicateOnDrag(pxtControlsForOfId, "VAR");
 
         // controls_for_of
         const controlsForOfId = "controls_for_of";
diff --git a/pxtblocks/loader.ts b/pxtblocks/loader.ts
index 4dd518c00d80..f946145c4a8b 100644
--- a/pxtblocks/loader.ts
+++ b/pxtblocks/loader.ts
@@ -23,7 +23,7 @@ import { initOnStart } from "./builtins/misc";
 import { initContextMenu } from "./contextMenu";
 import { renderCodeCard } from "./codecardRenderer";
 import { FieldDropdown } from "./fields/field_dropdown";
-import { setDraggableShadowBlocks, setDuplicateOnDragStrategy } from "./plugins/duplicateOnDrag";
+import { setDraggableShadowBlocks, setDuplicateOnDrag, setDuplicateOnDragStrategy } from "./plugins/duplicateOnDrag";
 import { applyPolyfills } from "./polyfills";
 
 
@@ -259,6 +259,11 @@ function initBlock(block: Blockly.Block, info: pxtc.BlocksInfo, fn: pxtc.SymbolI
                 } else {
                     i.setCheck("Variable");
                 }
+
+            });
+
+            comp.handlerArgs.forEach(arg => {
+                setDuplicateOnDrag(block.type, "HANDLER_DRAG_PARAM_" + arg.name);
             });
         }
         else {
diff --git a/pxtblocks/plugins/duplicateOnDrag/connectionChecker.ts b/pxtblocks/plugins/duplicateOnDrag/connectionChecker.ts
index 89983500234b..558095807492 100644
--- a/pxtblocks/plugins/duplicateOnDrag/connectionChecker.ts
+++ b/pxtblocks/plugins/duplicateOnDrag/connectionChecker.ts
@@ -1,5 +1,5 @@
 import * as Blockly from "blockly";
-import { isDuplicateOnDragBlock } from "./duplicateOnDrag";
+import { shouldDuplicateOnDrag } from "./duplicateOnDrag";
 
 
 const OPPOSITE_TYPE: number[] = [];
@@ -16,7 +16,7 @@ export class DuplicateOnDragConnectionChecker extends Blockly.ConnectionChecker
 
         const replacedBlock = b.targetBlock();
 
-        if (replacedBlock && isDuplicateOnDragBlock(replacedBlock)) return false;
+        if (replacedBlock && shouldDuplicateOnDrag(replacedBlock)) return false;
 
         return true;
     }
diff --git a/pxtblocks/plugins/duplicateOnDrag/dragStrategy.ts b/pxtblocks/plugins/duplicateOnDrag/dragStrategy.ts
index 1d05382535e1..6f5c937f484a 100644
--- a/pxtblocks/plugins/duplicateOnDrag/dragStrategy.ts
+++ b/pxtblocks/plugins/duplicateOnDrag/dragStrategy.ts
@@ -6,7 +6,7 @@
 
 import * as Blockly from "blockly";
 
-import { DUPLICATE_ON_DRAG_MUTATION_KEY, isAllowlistedShadow } from "./duplicateOnDrag";
+import { DUPLICATE_ON_DRAG_MUTATION_KEY, isAllowlistedShadow, shouldDuplicateOnDrag } from "./duplicateOnDrag";
 import eventUtils = Blockly.Events;
 import Coordinate = Blockly.utils.Coordinate;
 import dom = Blockly.utils.dom;
@@ -160,7 +160,7 @@ export class DuplicateOnDragStrategy implements Blockly.IDragStrategy {
 
         const mutation = this.block.mutationToDom?.();
 
-        if (mutation?.getAttribute(DUPLICATE_ON_DRAG_MUTATION_KEY)?.toLowerCase() === "true" || (isAllowlistedShadow(this.block) && isShadow)) {
+        if (shouldDuplicateOnDrag(this.block)) {
             const output = this.block.outputConnection;
 
             if (!output?.targetConnection) return;
diff --git a/pxtblocks/plugins/duplicateOnDrag/duplicateOnDrag.ts b/pxtblocks/plugins/duplicateOnDrag/duplicateOnDrag.ts
index 4b8d9aff2155..2d43955a33cb 100644
--- a/pxtblocks/plugins/duplicateOnDrag/duplicateOnDrag.ts
+++ b/pxtblocks/plugins/duplicateOnDrag/duplicateOnDrag.ts
@@ -3,21 +3,87 @@ import * as Blockly from "blockly";
 export const DUPLICATE_ON_DRAG_MUTATION_KEY = "duplicateondrag";
 
 let draggableShadowAllowlist: string[];
+let duplicateRefs: DuplicateOnDragRef[];
 
-export function isDuplicateOnDragBlock(block: Blockly.Block) {
-    return block.mutationToDom?.()?.getAttribute(DUPLICATE_ON_DRAG_MUTATION_KEY)?.toLowerCase() === "true";
+interface DuplicateOnDragRef {
+    parentBlockType: string;
+    inputName?: string;
+    childBlockType?: string;
 }
 
 export function setDraggableShadowBlocks(ids: string[]) {
     draggableShadowAllowlist = ids;
 }
 
+/**
+ * Configures duplicate on drag for a block's child inputs
+ *
+ * @param parentBlockType   The type of the parent block
+ * @param inputName         The value input to duplicate blocks on when dragged. If not
+ *                          specified, all child value inputs will be duplicated
+ * @param childBlockType    The type of the child block to be duplicated. If not specified,
+ *                          any block attached to the input will be duplicated on drag
+ *                          regardless of type
+ */
+export function setDuplicateOnDrag(parentBlockType: string, inputName?: string, childBlockType?: string) {
+    if (!duplicateRefs) {
+        duplicateRefs = [];
+    }
+
+    const existing = duplicateRefs.some(ref => ref.parentBlockType === parentBlockType && ref.inputName === inputName && ref.childBlockType === childBlockType);
+    if (existing) {
+        return;
+    }
+
+    duplicateRefs.push({
+        parentBlockType,
+        inputName,
+        childBlockType
+    });
+}
+
 export function isAllowlistedShadow(block: Blockly.Block) {
     if (draggableShadowAllowlist) {
         if (draggableShadowAllowlist.indexOf(block.type) !== -1) {
             return true;
         }
     }
+    return false;
+}
+
+export function shouldDuplicateOnDrag(block: Blockly.Block) {
+    if (block.isShadow() && isAllowlistedShadow(block)) {
+        return true;
+    }
+
+    if (duplicateRefs) {
+        const parent = block.outputConnection?.targetBlock();
+
+        if (parent) {
+            const refs = duplicateRefs.filter(r => r.parentBlockType === parent.type);
+
+            for (const ref of refs) {
+                if (ref && (!ref.childBlockType || ref.childBlockType === block.type)) {
+                    if (ref.inputName) {
+                        const targetConnection = block.outputConnection.targetConnection;
+                        if (targetConnection.getParentInput().name === ref.inputName) {
+                            return true;
+                        }
+                    }
+                    else {
+                        return true;
+                    }
+                }
+            }
+        }
+    }
+
+    if (block.mutationToDom) {
+        const mutation = block.mutationToDom();
+        if (mutation?.getAttribute(DUPLICATE_ON_DRAG_MUTATION_KEY)?.toLowerCase() === "true") {
+            return true;
+        }
+    }
 
     return false;
 }
\ No newline at end of file
diff --git a/pxtblocks/plugins/functions/blocks/functionDefinitionBlock.ts b/pxtblocks/plugins/functions/blocks/functionDefinitionBlock.ts
index d5fd4f48a8ab..94a30c7c2295 100644
--- a/pxtblocks/plugins/functions/blocks/functionDefinitionBlock.ts
+++ b/pxtblocks/plugins/functions/blocks/functionDefinitionBlock.ts
@@ -21,7 +21,7 @@ import { MsgKey } from "../msg";
 import { FunctionManager } from "../functionManager";
 import { COLLAPSE_IMAGE_DATAURI } from "../svgs";
 import { ArgumentReporterBlock } from "./argumentReporterBlocks";
-import { DUPLICATE_ON_DRAG_MUTATION_KEY } from "../../duplicateOnDrag";
+import { DUPLICATE_ON_DRAG_MUTATION_KEY, setDuplicateOnDrag } from "../../duplicateOnDrag";
 
 interface FunctionDefinitionMixin extends CommonFunctionMixin {
     createArgumentReporter_(arg: FunctionArgument): ArgumentReporterBlock;
@@ -205,6 +205,8 @@ Blockly.Blocks[FUNCTION_DEFINITION_BLOCK_TYPE] = {
     },
 };
 
+setDuplicateOnDrag(FUNCTION_DEFINITION_BLOCK_TYPE);
+
 
 function editFunctionCallback(block: CommonFunctionBlock) {
     // Edit can come from either the function definition or a function call.