Thanks. I tried to get a hardware Steam Link working with Gamepass games and failed, I either tried with that App or some other one I forget but ultimately I got it working by installing Moonlight on the Steam Link instead and essentially using it like a remote desktop.

I've read reports of Windows Store overwriting mod files, either this is a game by game problem or maybe it's solved. I do know a year or two ago the Window Store refused to open on a Windows PC of mine so it's a real problem and there's no way to easily reinstall the windows store if it occurs.

Whether Microsoft has solved these issues by now I don't know. I think I eventually got the windows store back with a Windows update.