I think I found a way to smooth out ADS. The advanced controls are different for sure. I played around with them a bit and the smoothest I seem to be able to get the ADS is to have the following settings:
(basic settings are really just your preferences)
Basic Controls: X Axis Sensitivity - 70%
Y Axis Sensitivity - 40%
(in advanced controls, I leave everything alone except the ADS)
*ADS*
--basically everything slid to the left within ads subsection, just typing it out for visual purposes--
Sens X - 20%
Sens Y - 10%
Exponent - 1
Inner Deadzone - 10%
Outer Deadzone - 70%
Rampup X - 100%
Rampup Y - 100%
PampTime - 0S
Ramp Delay - 0S
RampCooldown - 0.5X
This slows down the over the shoulder aiming as well. I generally play with higher control sensitivity but until the game gets polished more, this is helping me.
I hope this helps a bit :)