This is something that made me upset. When Rumple had the hat, he could’ve easily poofed it off back to his mansion; went to retrieve it after dealing with Anna; went back to get it; then make a deal with the Sorcerer to GET TO OUR WORLD. The Rumple through the past three seasons would’ve done this! This makes total illogical sense.
Rumple wouldn’t give up the hat to go through the door. He could just bring it with him to our world using the dark curse.