diff --git a/packages/iris-grid/src/IrisGrid.tsx b/packages/iris-grid/src/IrisGrid.tsx
index 108152133..66c0feb35 100644
--- a/packages/iris-grid/src/IrisGrid.tsx
+++ b/packages/iris-grid/src/IrisGrid.tsx
@@ -1498,7 +1498,8 @@ class IrisGrid extends Component<IrisGridProps, IrisGridState> {
     (mouseHandlers: MouseHandlersProp): readonly GridMouseHandler[] =>
       [...mouseHandlers, ...this.mouseHandlers].map(handler =>
         typeof handler === 'function' ? handler(this) : handler
-      )
+      ),
+    { max: 1 }
   );
 
   getCachedRenderer = memoize(
@@ -2531,11 +2532,18 @@ class IrisGrid extends Component<IrisGridProps, IrisGridState> {
     });
   }
 
-  toggleExpandColumn(modelIndex: ModelIndex): void {
+  toggleExpandColumn(
+    modelIndex: ModelIndex,
+    expandDescendants?: boolean
+  ): void {
     log.debug2('Toggle expand column', modelIndex);
     const { model } = this.props;
     if (isExpandableColumnGridModel(model) && model.hasExpandableColumns) {
-      model.setColumnExpanded(modelIndex, !model.isColumnExpanded(modelIndex));
+      model.setColumnExpanded(
+        modelIndex,
+        !model.isColumnExpanded(modelIndex),
+        expandDescendants
+      );
     }
   }