New question about OpenXR toolkit

[RackMonkey]

To find out if I've left any performance on the table I've begun playing with other setting, and the first one I choose is motion reprojection.

If it is on any other setting but OFF the display looks like I'm looking through a sheet of falling water. This seems to be a strange thing to do and completely different than when I had MR turned on in SteamVR. Does anybody know the what and why of this?

On a side note, what is the difference of turning on MR in the OpenXR tools and turning it on in game with the toolkit companion?