Also a few specific tips right from the recently updated MSFS zendesk if they help:
All versions - How to improve the performance – Microsoft Flight Simulator Support (zendesk.com)
If it’s a Win 11 machine, ensure VBS memory integrity is disabled. And if you’re running DX11, you can set low latency mode to on or ultra in the Nvidia CP.
With that GPU and resolution, you can run on the ultra graphics preset, but notch back render scaler to 85%-90%. Also try and keep the terrain LOD where it is if you’re trying to avoid stutters.
The other piece of equation is the display - are you running a g-sync or freesync monitor?