Hand tracking

I'm interested in the hand tracking, both for creating apps/games which use the hand tracking alone, but then i also wondered about these:
-will one be able to use the hand tracking together with the controllers, too?
So like then one could maybe have even better hand/finger representation in a game/app which uses the controllers
-is it also thought of to maybe extend this so it is not "just" hand/finger tracking but also lower/upper arm tracking?
So then one could show arms for the player and they would be perfectly where the real arm parts are instead of us guestimating it.
(sure could only track it during times those parts are in camera view, but that could already be a nice improvement, so whenever in camera view it could have the arm parts at the positions/rotations coming from the detection, and when going out of the detection it would fall/ease "back" to an IK or similar solution guestimation)
is any of this already known?