See the "Actual FOV" in the output when you select the aim: https://www.mouse-sensitivity.com/?share=bd9839b618ab351f98632e17aef7975a
(Enter your own resolution etc)
It's not affecting the conversion, it's affecting the game itself (R6). That's just how the game works, the 360 distance for ADS is derived from all the sensitivity values and the FOV of hipfire and ADS.