This post is a great starter on this type of haptic interface: Haptic textures - #4 by Antun_Skuric
Forget what you are thinking about electrical angle, it is not relevant to the physical angle.
This graph might help you conceptualize how it can work. What you want to do is similar to this, except rather than the shallow slope (spring-like) like this, you want it to be very steep (kind of like a step function, but you still need a bit of hysteresis), so that even small angle error will produce a large, flat (e.g. viscose, friction like) torque response. You could write some code to handle that when the angle starts to recover position (e.g. the knob is let go) then you set that as the center /stable point. I think for your case you don’t need to consider any attractor angle since it’s all continuous in your use case.
As far as cogging goes, you are at the mercy of your motor. For buying low cogging motors, see the ones used in the smartknob project, these seem to be the best on market for now.