We know the GoF's a timedoor better than the backs of our hands
But..........................
Remember the dialogue from “The City on the Edge of Forever”:
Spock: “If I am correct, a doorway to other times & dimensions
”
The GoF: “As is correct for you. For your level of understanding.”
I think I remembered that scene's words >90% right yes?
So, based on how The GoF answered Spock's inquiry:
Can The GoF be used to travel to/from alternate|parallel universes & etc?
Think of the places available then-
Mirror Universe(s), alternate universes from “Parallels”, fluidic space, the Q Continuum
& etc, etc
Of course, most, if not all, of the other universe's would have GoFs as well

But..........................
Remember the dialogue from “The City on the Edge of Forever”:
Spock: “If I am correct, a doorway to other times & dimensions

The GoF: “As is correct for you. For your level of understanding.”
I think I remembered that scene's words >90% right yes?
So, based on how The GoF answered Spock's inquiry:
Can The GoF be used to travel to/from alternate|parallel universes & etc?
Think of the places available then-
Mirror Universe(s), alternate universes from “Parallels”, fluidic space, the Q Continuum

Of course, most, if not all, of the other universe's would have GoFs as well
