Not sure if you saw my other post, but one of my issues that added to the confusion was that I never really had pure OpenXR mode. Due to a DLL that I forgot to delete OpenXR could not launch and DCS fell back to OpenVR, which in turn used SteamVR. So check the DCS log if it actually says OpenXR for you. Just another thing to consider. While I still don't feel the performance in pure FPS is better, OpenXR seems to have lower latency for me compared to native Oculus. So perhaps you would get the "smoother feeling" you noticed in SteamVR, but without the jitter if you run OpenXR?
As far as I understood it from one day of usage is that Motion Reprojection is only available for WMR headsets. Oculus uses Asynchronous Space Warp (ASW), which you can force in the Oculus Debug Tool prior to launching DCS in OpenXR mode. But for me ASW does cause extreme stutters in any mode since the patch (no matter if native Oculus, OpenXR or OpenVR/SteamVR), so I actually ensure it is disabled in the Debug Tool every time.