I’ve been trying to make Windows key work as Super key in Linux Mint (Mate edition),
as this would be natural after using Windows for quite a long time.

I tried Keyboard Shortcuts,
then searched for the keycode of the Windows key on my machine,
and when that didn’t lead to anything, I tried searching.

Seems like this is a known issue and WIP (hopefully, it will work some day) in Mate(
Here is the post I found:

Windows key (Super L) is not working.

That’s enough to stop searching for a while… Hmm.