I seem to have gotten mine back to "normal".
At 90Hz: I had to dial back SVRSS to 60% from my previous 80-100% (I ran tree heavy maps at 80 and Nevada at 100) both at 4x MSAA with motion smoothing enable and maintain 45 fps/15-7 GPU frametimes.
I decided to try setting WMR to 60Hz, and while yes there is a slight flicker in the sky, I've gotten used to it. Hardly even notice it now.
I can run my usual "High" in game settings, SVRSS 80%, NO motion smoothing (and no stutter), solid 60fps 10-15ms GPU frametimes.
Very enjoyable flight experience, readable cockpits, ZERO stutter.
I am running 1.2 Open FSR at .77, 0 sharpen. Reshade mod and the following other mods.