Surprised no one answered yet… I don’t have a steam deck, so I don’t know much about it. Are those games from the windows store? If not, you could try to get them working on linux with Lutris (or something similar). Generally I wouldn’t encourage buying DRM-free versions of games if possible (I know sadly that’s not an option for every game)
This is a good tip, if they are dual booting, but there is no reference to that in the post. I’d recommend to not dual boot. Less problems and no Windows