Hold something like this:
… Your perfect sensitivity
… The game where you want to transfer your perfect sensitivity
E.g. An 8 sensitivity in R6 is a… Sensitivity in Fortnite
No, this is nonsense because there are too many factors that affect mouse speed.
Simply adjust according to your feeling and good.
OK.
I gamble e.g. On two different screens with different resolutions. This already shows a difference in mouse speed. So I always have to adjust when I change.