Seems to work well when going from higher to lower FOV. Messes up when going from low to high FOVs I think.
E.g.:
BF zoom sens to pubg hipfire gives 28 with auto feature (screenshot 1). When trying to 'reverse engineer' the value you get 37. ( see screenshot 2)
I've actually had a bunch of succes with this aswell. Especially in games with big FOV differences (like PUBG) the smaller FOVs always felt too fast. This fixes this, higher magnifications like 4x and 8x feel great now.