Board Thread:General Discussion/@comment-26443838-20150621062143/@comment-24674051-20150623172334

Actually, as far as world travelling, I am hoping that one or more of the Mages can learn the Apprentices trick for making the portal door appear. That would be so convenient.

They don't need to revisit the curse, though. The scroll for the curse was destroyed when Regina reversed the first curse, and only Rumple and Regina know how to cast the curse. (well, and maybe Emma, assuming that the Dark One passes all knowledge between hosts).