I’m generally happy with my VR experience, running TAA 100, OXR 90 and finding it relatively sharp and smooth. I do find issues sometimes, when switching between VR and 2D while flying. When i switch back to VR performance is horrible. Often it fixes itself after a little while, but today it was stubbornly sticking to < 10 fps in VR, so i played around a little and managed to find an interesting way to get full performance back.
I tried a lot of things, switching on/off VR, pause/unpause etc. I even tried switching off the headset closing WMR and, re-opening it, to no effect.
In the end a simple change in VR rendering resolution did the trick. I changed to TAA 80, hit apply and save, then changed back to my original TAA 100 and could continue the game with normal/smooth fps. It seems this simple change resets something and allows it to work again.
Hopefully this can help someone else stuck in random performance holes.