I’ve got some of my own theories about the way that the Dark Curse has affected the Dark One curse. (Darker, dearie, much darker…)
Since everyone affected by the curse is now both, Rumple is now both Mr. Gold and Rumplestiltskin. As such, he has that human person superimposed on top of his underlying human self and the Dark One self. The return of magic did not result in his limp going away or his physical features going gold–just as Jiminy did not return to being a cricket and the fairies did not suddenly sprout wings. The Dark Curse fundamentally changed everyone it affected, both in their memories/personalities, and, where applicable, physically. It may be that Storybrooke itself is necessary to maintain aspects of the Dark Curse even when it’s been broken, thus why Regina could still activate Lacey, why magic resulted in the town line erasing the non-cursed self, etc etc. It may also be that because magic works differently in the land without magic (or at least Storybrooke), the dark one curse is weaker.
I think that the Mr. Gold part does, to an extent, balance out the Dark One part. I think that it also means, in this world at least, a kiss isn’t sufficient to break the DO curse. I was willing to argue that there were reservations involved in earlier kisses, but the finale kisses…yeah, I just can’t argue that anymore. So I think it either has to do with the cursed self or the fact that they’re in the wrong world. Maybe we should pester Adam on twitter.
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing