Rather than mash up just the finales, I would take the aspects I liked from Season 7 and incorporate them into Season 6. I'd cut out Rumple going mad villain and screwing the Evil Queen in 6a and work on him proving himself to Belle and showing that he can be a good man for her and their unborn son, thus making his redemption at the end of the season far less rushed and without the need to give him a whole extra season without Belle. I'd also cut the entire falling out between Regina and Zelena which was random and forced, thus allowing more sister moments like we got in Season 7. Besides that, the only other thing from Season 7 I'd be missing is Alice, but I could live without her. The United Realms with Regina being crowned as the Good Queen was a nice idea for Season 7, but I was equally satisfied with the less over-the-top version we got of that in 6x22 with Regina and the dwarfs. I preferred the Black Fairy being the show's final villain, but Season 6 should've introduced her sooner and fleshed her out better. Not a fan of Gothel or anything involving Wish Realm counterparts.