There's a mouse polling bug in the game engine that's causing mouse stutter. The game engine is polling the mouse at 125Hz.
It's not even a consistent 125Hz. It's an inconsistent and choppy 125Hz.
It will require a code fix of mouse input by the game developers. So far they haven't acknowledged the mouse stutter bug exists.
PSA: Mouse Input is broken in this game looks similar to bad frame timing | EA Forums - 12734467
Okinouko, tested BF6's polling rate with MouseTester
BF6 125Hz mouse polling rate test
8ms polling = 125Hz
1000ms ÷ 8ms = 125Hz
