This post/thread may be helpful:
or
I have a G2 and have the store version of MSFS rather than steam. There are some comments in the attached threads about steam vr being a little worse performance wise, but with your hardware it shouldn’t be a slideshow. There’s some good stuff in here about lowering the rendering resolution when using motion reprojection that might be helpful.
My experience is good - i9 10900K, 64Gb ram, rtx 3080 with the G2. I;m sure with your hardware you can get there too.