>While you can drag from the project manager, you cannot drag controls into a grid column from there.

Correct.

Drag and Drop them onto the form.
Select the item on the form.
Ctrl-X to put it on the clipboard.
Paste into the grid column of your choice.

It is a workaround, but I agree with the original post.
Changing the toolbar is just inviting yourself to select controls from the wrong folder.