The Wayland spec doesn’t allow for clients to arbitrarily get clipboard data under typical conditions. Since most applications these days are running under Wayland, it should be that copying to the clipboard isn’t exposed to X11 clients most of the time (only when copying from or pasting into XWayland).

Considering Beat Saber already works on Linux just fine, and it isn’t particularly demanding/runs fine on less powerful standalone headsets, I imagine it’ll work.