UnknownUnknown
-dx11
If you don't use the -dx11 flag it crashes with a "fatal error!" dialog window.
-dx11
As stated by the other reports, by default the game does not display in your headset. Only the usual VR grid is shown. By launching the game in DX11 mode by adding the -dx11 flag to the launch options, the game is displayed correctly.
I tried running the game with Proton Experimental or GE at first, but with those I only encountered a "Fatal Error". So just run with default Proton and you should be good.
I also tried launching the game using Envision / Monado, which worked as well using the -dx11 flag. Without any launch options I got an error saying dx12 is not supported, which is how I came to the workaround of trying out dx11.
There should probably be an obvious way of launching the game in dx11 mode with a selection screen, like some games do.
Starts up but only shown on monitor
The game will start and correctly displays on my monitor but not on my Index headset.
Game starts in the screen instead of the headset. Controllers still work (Valve Index)
Opened a bug report for it: https://github.com/ValveSoftware/Proton/issues/6106
