@rbernon I found the patch that adds SEND_HWMSG_RAWINPUT flag[1]. I guess I did see that one in Proton! These changes allow finer granularity. For example, the graphics driver can be in charge of rawinput MOUSEEVENTF_MOVE but not button presses (etc...). Also if the graphics driver does not support rawinput the server will still be able to generate them.
[1] https://gitlab.winehq.org/wine/wine-staging/-/blob/master/patches/user32-raw...