@arcanicanis SteamVR isn't (or wasn't, it doesn't even want to start now after I fiddled with the betas and proton versions; not even after returning to a know working combination) the problem. I could start up SteamVR, get video to my Index, see my lighthouses, see my controllers, have tracking; the whole shebang, but as soon as I try to launch a VR game nothing happens. The game shows up green, so Steam thinks it's running, but the process never starts.