The add-on uses the Xenforo permission system so you can give permissions the same way you give permissions in base Xenforo.OK, thanks!
I'll install it to investigate and test.
1- Can the User notes be "replied to" then?
In cases where there is follow-up on a situation, to clarify details, mark it as [Solved], etc. Issues that require moderating usually go from innocent mistakes to abusive behaviour . It could be good to have a way to follow-up. I'm trying to see how this could be done.
2- Could I give permission to individuals, not necessarily to whole user groups?
The user notes isn't meant for replies. Enabling replies would create the need for pagination and would turn the user notes into threads. My suggestion is to link a thread in an user note if you want additional comments tracked. Think of an user note as a write up that one might perform on an employeel.