I'm not sure how much this helps, but here goes:
I had the same issue (also using openXR version) couldn't figure out where to put the files as the zip and OVGME didn't place them in the correct 'bin' folder. I guessed based on this forum thread (see before and after screens below).
Ran 3DMigoto Loader.exe from this folder.
With this configuration the loader starts without errors, but I get errors trying to load DCS – something to do with OpenXR (I think it said error code 13) so I still have not got it working. So it appears the mod is starting up at least?
All I want to do is remove the AH-64 rotor as it's full of attracts with motion reprojection – everywhere outside of the rotors is silky smooth now using the OpenXR mod.
Anyone have any ideas how to get this working or how to just remove the rotors if that's a simpler hack? Thanks.
Also: just saw this from the OP/Mod author. May help:
"I did not update the troubleshhoting guide for openXR but main things are the same : make the standard 3dmigoto mod working without any other mod, on a cleaned DCS install. Then try to install other mods and check impact. So please try to test on standard steamVR configuration before looking for OpenXR...
Once you'll have it working, uninstall the normal version, install the openXR mod and the opnXR version of 3dmigoto mod, and have a look on [DCSinstallationDirectory]\bin\3dmigoto..."