I saved this graph a while back when someone in this forum posted their 5600X to 5800X3D upgrade experience in MSFS VR:
As you can see, negligible improvement in average FPS but a notable improvement in 1% and 0.1% lows in some cases. ie. similar FPS but smoother after the upgrade. The improvement coming from a 5800X instead of a 5600X would be even less.