Do you have Hardware Accelerated GPU Scheduling and Game Mode off? Both can create sync problems between the CPU and GPU which results to stuttering in VR. To check search for “Graphics Settings” and “Game Mode Settings” in Windows. If you still get stuttering after that I would change the encode resolution width and the bitrate to their defaults in the Oculus Debug Tool, set the “Pixels per display pixel override” to 2, then go to MSFS and change the Render scaling to about 50/60 and TAA enabled. What this does is it uses MSFS’s TAA upscaling and Oculus’ super sampling to render at a low resolution and output a higher resolution image to the Quest’s display. You can try different combinations like Render Scaling set to 60 and the pixels per display pixel override set to 2.2. Play around and try to find a balance between resolution and fps.
I personally use 90 render scaling in-game and 1.2 PPDPO in the Oculus Debug Tool. I have a Vega 56 and I found that it strikes a fine balance between visuals and fps.