Add frames around each asset in the Assets panel even when not selected

[Frozen Death Knight]

The latest improvements to the Assets panel to improve visibility is much appreciated. That being said, I wish that assets had frames around their thumbnail borders at all times to be able to distinguish the difference between assets that lack a proper thumbnail and the background. For instance, "empty" Groups, Adjustment Layers, and Mask Layers don't have visible thumbnails, which to me is not a problem in of itself. It is however very hard to see if there even is an asset on the list with these qualities unless you hover over or select it.

Here's a Mask Layer asset when I select it:

This is how it looks when the asset is not selected:

Pretty much indistinguishable from the background. Adding frames around each asset would make it a lot easier to spot assets that are lacking thumbnails.

It also would be cool if Mask Layers had their black & white thumbnails visible like in the Layers panel, but the above suggestion would still suffice.