I noticed that on pc, steam controller can’t do mouse emulation. Likewise, steam link and moonlight can’t stream mouse input on to the game either. Most likely ‘emulated’ mouse input is being blocked by the drm. But on steam deck, using the track pad and gyro as mouse has no such issues. I would guess that the drm running in proton does not go deep enough to intercept the emulated mouse and can’t block it. If that is true, one might be able to use linux/proton to cheat, rendering the whole point of the rootkit drm useless.