I simply can not find a magic recipe for worthwhile motion reprojection performance. The OXRTK developer has corroborated several deficiencies with how AMD graphics cards currently work with VR in general. Definitely a couple steps behind nVidia.
Also, AMD doesn’t support many features in DX11 like nVidia does, and with DX12 still in Beta and not entirely stable for everyone, you have to take the DX12 bugs just to enable certain things on AMD (one example is fixed foveated rendering is not supported by AMD on DX11).
I have an RX 6800XT and HP Reverb G2.