So, I’m not sure if I should post this here and if anyone finds it problematic please comment!
It’s in InstanceCullingMergedContext.cpp
I literally just “disabled” the check for the Hierarchical Z-Buffer and with a Source build of 5.2.1 and this little change I can run the Full demo in VR.
I havent built the project with this change though, so take this solution with a lot of caution!
Line 124: check(PrevHZB == nullptr || PrevHZB == GraphBuilder.RegisterExternalTexture(Context->PrevHZB) || PrevHZB != nullptr);