Way to add a "shadow" to pieces such that it doesn't obscure

It seems that Vassal is so close to allowing this, but falls short. Is there some way I can implement it?

The game uses blocks, and the orientation of the blocks is important (upright, on side).

I want a top-down view and not an awkward forced isometric one.

I figure the best way to do this with a nice in-period visual effect would be to add “shadows” to the blocks to give them more board presence, and indicate shape and height.

However, I don’t want to use a simple piece with the shadow as part of the image if I can avoid it, because that would result in the shadow overlaying adjacent pieces.

Is there any way to attach one piece to another such that it is on a different layer? Or some other workaround? The area effect trait almost does it, but can’t be customised.

I appreciate that mere " visual effects" are pretty low priority, but any help would be appreciated.