SteamVR stuck at launch with error (with key component inst working / 303)

[bucketsize]

Stuck at "Something is wrong A key component of SteamVR isn't working correctly. Please reinstall SteamVR (303).

Only errors of interest I found were:

# vrclient_steam.txt
Mon Oct 02 2023 15:26:21.091139 [Info] - Unable to load driver linus_trinus. Primary driver shared library not found on filesystem (for this architecture): /home/jb/.steam/debian-installation/steamapps/common/SteamVR/drivers/linus_trinus/bin/linux32/driver_linus_trinus.so.

# vrcompositor.txt
Mon Oct 02 2023 15:21:45.497452 [Error] - CHmdWindowSDL: Failed to create direct mode surface
Mon Oct 02 2023 15:21:45.497591 [Error] - CHmdWindowSDL: VR requires direct mode.
Mon Oct 02 2023 15:21:45.497801 [Error] - Error making window!
Mon Oct 02 2023 15:21:45.510013 [Info] - Failed to kill gpu-trace
Mon Oct 02 2023 15:21:45.510098 [Info] - Failed to initialize compositor
Mon Oct 02 2023 15:21:45.510121 [Info] - Failed to start compositor: VRInitError_Compositor_CannotDRMLeaseDisplay

Just wondering if

• steam requires the 32bit linustrinus driver, or
• the X11/lxde which uses Openbox WM, is supported.

I'm on Debian bookworm with steam installed from the official repos.