If Hat Trick events happened after Regina took the Huntsman’s heart, then that means she had her vault before Hat Trick.
Unless this happened sometime between when Leopold died (and Genie went into the mirror) and when she hired the Huntsman, but I don’t think so because there didn’t seem to be a big space of time between those two events. We see Leopold’s coffin at the start of Heart Is A Lonely Hunter, so if Hat Trick was pre-Huntsman, that means she went to Wonderland twice in the middle of Heart Is A Lonely Hunter, (once to get her father, and a second time to bring the vault back), which isn’t likely.
Therefore, Hat Trick had to be after the Huntsman.
So if the QoH vault is the same one Regina had, QoH had to steal it at some point after the Huntsman’s heart was stashed inside. And if the QoH vault had Regina’s hearts in it, would she really have just taken that one box with her father inside and left the rest in Wonderland? That’s what’s making me think there are two vaults.
Does that make sense? Honestly, this ep has fried my brain like no other. LOL