A two queen colony with a queen excluder separating colonies.

1. Is this a nuc type situation or can you grow this colony to share a honey super? A Qn X would be necessary between brood super & Honey super.

What is the benefit of a 2Q colony vs two individual colonies?

If you can peacefully & productively maintain a 2 Qn colony, what is to stop you from a Qn bank type box w/Qn X separating any others? (room for brood?)