As far as I can figure the Snow/Charming and Emma/Henry TLKs were purely for the parallels from season one. Nothing else about them makes sense. Once loves character parallels and they will jump through any hoop they have to to get a Charming a chance to say some variation of ‘I will always find you’ or a Stiltskin to be abandoned as a child or to abandon one of their own kids or I don’t know make a rum joke at about Hook.
Don’t get me wrong I love a well written parallel as much as the next person, but it has to fit the story and make sense. I don’t know why the Once writers keep missing that point.