I know this is old, but I'll answer it just in case for the future
Just looking at the code it seems just to be typescript and electron. So technically speaking all you have to do is find the three.js camera object it's using. Maybe they're just wrapping it with their own abstraction or something. They could be contaminating the source of three.js and modifying the behavior for their own uses like prototype, but that's really looked down upon.
[edit]
Just looked at the code here. And just as I suspected, they're wrapping the three.js class with one of their own. You should be able to access it with the property "threeCamera" or "unifiedThreeCamera" on the Superpowers camera class.