There’s one old game that works better by chosing “Scaled by the system”; however this make other x11 apps look slightly blurry. Is it possible to either choose “Apply scaling themselves” and exclude one app from it, or exclude every other app from “scaled by the system”, so it only affect this one game?
A lot of things would be technically possible, but pulling that off in practice is quite challenging. Synchronizing the clipboard with one Xwayland instance is hard enough…
That’s not to say it will never be done, but it won’t happen anytime soon.