One easy suggestion that can be added in the next patch version
I personally made a custom icon for myself and assigned it on my system:
Generally, I just wanted to see faster tilesets between other text-based files in the asset folder or other tilemaps (if you chose to open .tsx with Tiled - then maps and tilesets have the same icons).
So that’s my suggestion
Here is the solution for setting custom icons per file type in Windows 10:
And an example in the context of the samples directory from tiled: