Your framerates not too shabby for a flight sim, even top gear PCs struggle with this sim at Ultra settings, even at less than 4K. Try and get a balance between the CPU and GPU loads and aim for smoothness rather than just FPS. Having a G-Sync or Freesync monitor would help a lot with any judders, as a smooth 35 fPS say is perfectly fine in a flight sim…it’s not a shoot 'em up after all.
Have you read through this thread? It breaks down one guy’s settings to attain a good smooth balance between visuals and performance.