Please look into adding built-in parameters for relaying if a user is in TPose/IKPose calibration for additional toggles.
A good example is to allow creators to take advantage of the T-Pose situations. I wanted to add a sign to the front and back of my avatar that says "Calibrating, do not disturb!". Other good examples could be toggling a loading animation or shader change for cool effects while calibrating.
I recently tried to implement my own TPose custom layer with a clip and realize it'll always run the state even if you're not calibrating, so even if my custom clip were to toggle the object on, it would stay on when you exit calibration. I am not sure how to make a proper exit to toggle the game object off.