I have explained many times on the forum that there is no “MR in MSFS”. The “Reprojection Mode” under VR setting is misleading, it is NOT Motion Reprojection, and is not related to the setting in OpenXR Toolkit/OpenXR Tools.
See this first post under FAQ (very last question): Motion Reprojection explained
Then the difference between OpenXR Toolkit and OpenXR Tools options is explained here:
Hopefully this clarifies things.