diff --git a/src/org/labkey/test/components/ui/grids/EditableGrid.java b/src/org/labkey/test/components/ui/grids/EditableGrid.java
index f4a98faf73..fb0e315767 100644
--- a/src/org/labkey/test/components/ui/grids/EditableGrid.java
+++ b/src/org/labkey/test/components/ui/grids/EditableGrid.java
@@ -1034,39 +1034,9 @@ public String copyCurrentSelection() throws IOException, UnsupportedFlavorExcept
         return getWrapper().getClipboardContent();
     }
 
-    /**
-     * Select a cell range and drag-fill from the end of that selection to {@code dragEnd}.
-     * Because this overload owns the {@link #selectCellRange} step, it can fully restore state
-     * and retry if the first drag extended the selection without applying the fill.
-     *
-     * @param selectStart first cell of the selection (passed to {@link #selectCellRange})
-     * @param selectEnd   last cell of the selection; also the source of the fill value
-     * @param dragEnd     destination cell for the fill drag
-     */
-    public void dragFill(WebElement selectStart, WebElement selectEnd, WebElement dragEnd)
-    {
-        Locator.XPathLocator selectionHandleLoc = Locator.byClass("cell-selection-handle");
-        selectCellRange(selectStart, selectEnd);
-        selectEnd.click();
-        String fillValue = getCellValue(selectEnd);
-        WebElement selectionHandle = selectionHandleLoc.waitForElement(getComponentElement(), 2_000);
-        dragToCell(selectionHandle, dragEnd);
-        if (!WebDriverWrapper.waitFor(() -> fillValue.equals(getCellValue(dragEnd)), 3_000))
-        {
-            // Fill didn't complete — the drag likely extended the selection without triggering the fill.
-            selectCellRange(selectStart, selectEnd);
-            selectEnd.click();
-            selectionHandle = selectionHandleLoc.waitForElement(getComponentElement(), 2_000);
-            dragToCell(selectionHandle, dragEnd);
-            WebDriverWrapper.waitFor(() -> fillValue.equals(getCellValue(dragEnd)),
-                    "Drag fill did not populate end cell with value: " + fillValue, 5_000);
-        }
-    }
-
     /**
      * Drag-fill from {@code startCell} (which must already be selected / part of the current
-     * selection) to {@code endCell}.  Prefer {@link #dragFill(WebElement, WebElement, WebElement)}
-     * when the selection range is known — that overload can retry reliably.
+     * selection) to {@code endCell}.
      */
     public void dragFill(WebElement startCell, WebElement endCell)
     {
@@ -1077,6 +1047,21 @@ public void dragFill(WebElement startCell, WebElement endCell)
         selectionHandleLoc.waitForElement(endCell, 5_000);
     }
 
+    /**
+     * Select {@code selectStart} through {@code dragEnd} and fill down from {@code selectEnd}'s row using Ctrl/Cmd+D.
+     * @param selectStart top-left cell of the range to select
+     * @param selectEnd   cell whose value will be filled down (must be in {@code selectStart}'s row)
+     * @param dragEnd     bottom-right cell of the range to select and fill down to
+     */
+    public void fillDown(WebElement selectStart, WebElement selectEnd, WebElement dragEnd)
+    {
+        selectCellRange(selectStart, dragEnd);
+        String fillValue = getCellValue(selectEnd);
+        new Actions(getDriver()).keyDown(MODIFIER_KEY).sendKeys("d").keyUp(MODIFIER_KEY).build().perform();
+        WebDriverWrapper.waitFor(() -> fillValue.equals(getCellValue(dragEnd)),
+                "Fill-down did not populate end cell with value: " + fillValue, 3_000);
+    }
+
     public void selectCellRange(WebElement startCell, WebElement endCell)
     {
         dragToCell(startCell, endCell);
@@ -1195,8 +1180,9 @@ private boolean isInSelection(WebElement cell)  // 'in selection' shows as blue
     {
         // Should not need to add code for a reactSelect here. A selection involves clicking/dragging, which closes the reactSelect.
         return Locator.tagWithClass("div", "cellular-display")
-                .findElement(cell)
-                .getDomAttribute("class").contains("cell-selection");
+                .findOptionalElement(cell)
+                .map(el -> el.getDomAttribute("class").contains("cell-selection"))
+                .orElse(false);
     }
 
     /**