What I want on macos is that Finder can't have focus if there are zero finder windows on top and the desktop is not fully uncovered, maybe not even then. What already happened once for me is that I accidentally triggered undo thinking I had Firefox focused, because that was the visible window, and I failed to look at the menu bar, so instead I managed to undo a copy or move action in Finder, I'm not even sure what it was, because all you get is a plink sound and Finder doesn't help you figure out what you just did. It's a recipe for disaster, I imagine I could unknowingly screw things up big time.