Hi Shawn,
Yes, this is (so far I can tell) not specified in any tutorial nor in the manual itself. Which indicates to me, that it works like an average Controller, but in this case it has only a few functions.
There are two types of these, one the has the abbreviation “nb” in it and one that has not. (I would say it stands for “not bendy”, as in bendy or not bendy character set up). While you click on the controller, the Component (as shown in the Information/editor view) is activated, even the Object manager isn’t displaying the Component. This activates as well the Key Frame selection, to filter for example Auto Keyframe information. It also shows, while in Attribute Manager, Controllers view, the specific parameters.
I haven’t found any other function so far that would add any user interaction options here, perhaps one of the Character Instructors can add some information. I could find in the character hierarchy any link to IK/FK tags.
All the best