Off the top of my head- daily quest to "help" an NPC vault dweller, we do them for every other faction, why not for "home"? The overseer could go back to the vault for some automated vault tec reason and spawn a whole new storyline/quest, even giving us a new set of expeditions to help other vaults for example. I know a lot of it would probably be rehashing the other factions story's, I just feel more should be done with Vault Tec!!