would it be possible to have duty support for small parties instead of only solo?

[Enkidoh]

As I understand it, SE have explained why it's not possible to do this in the past, as it is due to how the NPCs are programmed - the NPCs are coded to follow your lead and respond accordingly while trying to follow dungeon mechanics, so if there was more than one player in the party they would start to get 'confused' and would glitch or act in strange ways, not knowing which player to 'follow'.

Either way SE deemed it was just too much trouble to have to deal with for the small benefit it would give, so alas Duty Support is designed for only a single player and will always remain as such I'm sorry to say.