vorpX itself doesn’t provide any shortcut/keypress for activating passthrough.
Sounds like it could be useful from time to time. I’ll check whether there is some way to enable it from within an application, not sure whether the Oculus SDK has that functionality though.
That doesn’t automatically mean that any developer can do it too. Oculus can do it, of course. Whether they allow app developers to do it is a different question. May or may not be the case.