Also as a heads up, some findings through a couple of searches on youtube that I've tested that seemed to add up:
-If you want a 1:1 hipfire-to-ADS sensitivity, you need to take your standard sensitivity (the first input on both sections of your sens) and multiply it by 2.6.
-Make sure your DPI isn't set higher than 800 (or maybe even lower it down to 400?) since your turning speed seems to be "capped" at higher DPIs, regardless of your sensitivity ingame. I can only imagine this is due to their current engine added onto the fact that they're running the game through an emulator. Its jank but you can make it feel "right" if you get the settings correct.
Keep in mind these sensitivities can be changed per user preference but for 1x/iron sights, you typically want to keep those values 1:1.