I see why you think that, but it's not the same thing. A crossover point is more like, I don't know, a curtain? It's a point between two planes where the divide isn't as secure, so things can slip through. The Door's an actual portal.

[He doesn't quite understand how it all works on a scientific level, but he does know it's not the same.]

No, she's not, which is why I think I can reason with her.

[Maaaybe.]