@iska@mstdn.starnix.network GTK had some environmental variable to force wayland, I'm not sure if you still need it, maybe it detects this automatically. SDL apps still needs some var to use wayland backend.
BTW if you are serious about going the wayland route, try Alacritty. It's fast on wayland (I always thought of it as wayland-only, found out that it works with X11 only a month ago 😆) and really good.