interesting post not time I update my drivers might give a reinstall a go.
actually I got a significant increase in fps from the last patch and running it now with reprojection off - runs very smooth with no jitters and my fps is around 30-40 (note I found the game changer for me was setting the rendering in OXR to 50 but leaving rendering in game to 100.
never got the reprojection to improve on this - in the OXR frame counter I was jumping between a red and blue screen - with full motion reprojection on then it would jump to depth reprojection on with lots of jitters - not sure if its bug or my 2080ti was struggling to run it…