I've seen it come up a few times that people make it off Stowaway's Step and have trouble finding another bank. Obviously we know it's in Port Azure, but I know my initial playthrough I also didn't leave Hidden Hills until another several hours had passed and I'd been through Bonepits and Vitheo's Watch many times.
I don't think adding a Banking NPC to the settlement in Hidden Hills would negatively impact anything and help be a sort of stepping stone for people as they make their way through the beginning of the game.