As an AMD user on Wayland who primarily uses Steam/Proton, I haven't had any Wayland-related issues with gaming at all. This isn't surprising, since the compositor used by Steam Deck (Gamescope) is also Wayland-based.
FYI: If you ever do have compositor-related issues (X11 OR Wayland), you can almost always fix the issue by running the game in a nested Gamescope instance by editing the game's launch command.