For technical reasons that I am not able to explain, the switch to W10 has improved fluency by reducing stuttering.
Not saying this is the culprit but anything is worth trying. I noticed in the OP's video, it looks like the FPS display, top left, is from Steam Overlay. I turn the Steam Overlay off, I don't sign into Steam Friends. Basically I turn everything in-game related off in Steam, alerts, notifications, displays, broadcasting blah blah blah. I also have the rF2 Launcher set to Auto Close.
I have fixed my stuttering problem by setting the game in fullscreen. Previuously I had the game set in "windows borderless" because I needed to use SimHub in overlay. But setting the game in this way I can't activate any vSync. Now, in fullscreen with vSync video, I have 60FPS every time and the game never stutter. Obviously I can't use SimHub.
