AMD / OPENXR / Motion Reprojection / AMS2

I'm trying to get Motion Reprojection working on a system with 6900XT GPU.

Unfortunately whenever I try to enable it, it simply crushes my fps. Under favourable circumstances (90fps / 30-40% headroom) whenever I enable it, it drops the fps to 20.

I tried all combination of settings: Enhanced / Original / best frame rate, 1/2 framerate, etc. / Prefer frame rate over latency on/off. Nothing works. Whenever it is enabled, my fps is crushed. https://routerlogin.uno/

I want to use Motion Reprojection as a buffer for certain conditions, but unfortunately I am unable to.

It has always behaved iffy on AMD cards, but at least it used to work much better. SteamVR works flawless, but fidelity is worse.