Sorry wasn't super coherent when I wrote that. I just read it back, your helicopter rotation is locked to a certain rate by the game no matter how high your sensitivity. The momentum of the Helicopter changes differently based on frame/tick rate. A high tick-rate means more updates to the momentum value and direction per second. A low tick-rate means that updates to momentum are less frequent and you can therefore rotate the heli more before the momentum change is applied. In my personal opinion, it's fine so long as the framerate cap isn't changed mid-run.

Sub 4 definitely possible

Basically, your turns are more responsive on higher framerates but you carry more momentum on lower framerates.

The main difference is lower framerate carries momentum I'm not entirely sure how the game calculates it but your turns are way more responsive on higher framerates. I primarily fly on servers where it's tick rate based and typically pretty low (About 20-60) and that's what I'm used to so it's easier for me to fly on lower tick-rates. This is something that is somewhat well known on the pilot community side of squad but not well understood. The main reason this is known is you can't do jhooks like in the video below:

Here's a run at 60 FPS framelock you may be able to see some physics differences.

It's not mentioned in the rules anywhere but helicopter physics in squad is heavily tickrate dependent, so when you're on the pilot tutorial that directly translates to framerate. I primarily fly in multiplayer so I am used to flying at a lower tickrate is capping framerate allowed?