So! I am not entirely sure what the use case is, and what exactly you mean by changing controller 
I mean - I understand you have a few states to a single controller, but why would you need 3 controllers for that (unless I am missing something).
To answer your direct question - controllera re initilized by the webxr environment, so you can’t initialize the same controller 3 times. What you CAN do is have some form of state control for your controller. Attach yourself to the controller’s observables, and according to the current state of the experience, react differently to the user input.
And again - if I misunderstood something, please let me know