why dont you try add index support (or you cant??)
Ever heard of revive? With that you can play oculus exclusives on vive, index etc. This game doesnt work on steamvr headsets because he used openXR instead of openVR. reviv changes openVR headsets into openXR.
sadly I don't think revive works for this, I tried all day yesterday
Valve doesnt have inputs for XR working yet.