You’re a life saver @GrapeJuice12345 !! Followed your settings for OpenXR + OpenXR tookit and used @Deelee6800 's settings in game. Sitting comfortably at 40 FPS now at full resolution on the Reverb G2 with a 9900k, 3080ti and 32GB of RAM. I dip to the high 20’s here and there in really busy places (like downtown city cores close to the ground) but this is GAME CHANGING. Game is actually playable and enjoyable now.
One thing to note, don’t switch in and out of VR, start VR BEFORE loading your flight and keep it on the whole time. If it’s a long flight, you’ll need to come back from time to time to prevent the headset from timing out. There’s a bug that can often render the sim unusable as FPS slows to a crawl (both in VR and non-VR) that’s gone unfixed for more than a year as far as I can tell. No known workaround although if anybody knows of any, please let us know! Thanks again folks, great tips on this thread.