PSA: Mouse Input is broken in this game (looks similar to bad frame timing)

I'm not 100% convinced about the polling rate being 125hz when the game is running. If I set polling rate to 1000hz, the game looks jittery, like we're all experiencing. But if I set mouse polling rate to 125hz instead, it looks much worse. If Windows was treating the game as a background process and polling at 125hz, shouldn't changing mouse polling rate in Ghub from 1000hz to 125hz make no difference? And also, if the game polled at 125hz, shouldn't even the mouse cursor in the menu be jittery/choppy? It seems unaffected from what I can tell. And not to mention, when in vehicles in third-person view, the camera was smooth too. Although that has now been broken for me since the S2 patch and now a number of vehicles have a very choppy camera movement when in third-person (dirtbikes, quadbikes, jeeps, mrap).

Although, I do also find it interesting that if I cap FPS in-game at 125 it completely fixes the problem, except for it going haywire every 5 minutes for 30s, where it looks very choppy again (even worse than the regular jitter when FPS is locked at 138). But it is interesting capping to 125fps does seem to sync up with something the game is doing, so maybe there is something to a 125hz poll rate. But then if the game is polling the mouse at 125hz, shouldn't setting FPS to anything below 125 also not exhibited issues? Because if I set my FPS even to 124, the jitter returns. However, when people were all posting specs and info, capping FPS to 125 didn't work for everyone by the sounds of it.

Either way, what a mess. At least the DLSS issue I was having has been fixed, but this one is such a major issue it's baffling and frustrating.