Another one bites the dust :D
This was relatively fast since the AI had F3 already done so it just took the code and adapted it to NV, wasn't immediate I still had to test but eventually we got there.
The approach is the same as all the other fixes, Responsive Interpolation Layer (RIL):
decouple game logic from rendering (this could simply mean multiple display, or 'presentation' frames for each real logic frame)
interpolate all world positions, rotations & animations in non-logic frames towards the next logic frame
add a per-frame mouse delta override to restore mouse input latency to 240hz/whateverhz levels
I'm spamming these ones all at once (all Frictional Games plus this one) I'll update the post if anything else comes to mind!
Fallout: New Vegas FPS RILView fix → See ya.