Vertical look doesn’t have acceleration, so I think the game feels best with at least a vertical look sensitivity of 7. This gives you the ability to quickly throw nades at your feet, track jumping and dropping targets, and track targets while you’re jumping and dropping. It also makes it a big easier to snap up to a targets head at the end of a BR fight.
I think you’ll like it.
I used the suggestions from Ubernick’s video on the topic as a baseline and made slight adjustments from there. IMHO he was generally in the ballpark.
Simple advice is to keep sensitivity, acceleration, etc on default. You’ll adapt to any settings you choose after a little while. I know people who go through sensitivity crises all the time and I mostly stay on default in every game. I change other settings but not aim settings unless I find it too slow. Some people want to hop up to 10 sensitivity before they have mastered a steady shot on 5 sensitivity