I think the rules behind the hat are put in place as a sort of fail-safe, by the person who imbued the hat with magic; who in this case I think would probably have to be one of the fairies, I'm thinking the Blue Fairy in particular. Seeing as we've seen the Blue Fairy work with other FTL characters before ( Cinderella – to help capture & imprison Rumpelstiltskin / as well as Snow & Charming, seeing as she was a part of their council meeting & she was the one who assured them that Gepetto would be able to craft a safe passage for baby Emma; the wardrobe. )
So I don't really believe that Jefferson is a magic user. Both in SB & FTL he just happened to know the rules/laws of an object that had been imbued with magic. Otherwise, he wouldn't have gone mad in Wonderland trying to make another magic hat. He would have made one & been done with it.