naz TEST FPS.trk
Hey naz, for what it's worth-
When I played your track as you were panning around the cockpit I did see FPS swings like you described. However on my machine FPS were consistent throughout t the track.
Using the highest settings @ 5760x1080 the final FPS were
current 65
average 56
highest 93
lowest 10
Link is included for others to try…