I've never tried to add someone into a party without having their member address, so I wouldn't know. But there is an option here -- [ points at the phone icon ] -- for parties, so perhaps you can! Ahhh, the map works outside of town, too!

[ She moves her finger down to point at the gears icon. ] This will show the items you hold, although it's the only way to retrieve items from your bag. [ Ada takes a moment to pause. ] It's quite curious, but I've learned not to question it.