Two Shelf Mushroom Placement heights, one flush with the top edge of blocks

Shelf Mushrooms would have even more potential in builds if they were flush with the top edge of a block. As small shelves or ceiling stucco, for example.
However, this would make them look worse as actual mushrooms.

The solution: two placement variants, like top/bottom slabs, to place them at the top or center of a block.

Even when used as actual mushrooms in builds, this allows groups to look less uniform, another commonly noted problem.

(As suggested by Reddit and wildly popular there, but hasn't been posted to any official channels from my search)