I only figured out individual departures because I cheated and injected my group with trackers. That way we always knew where one of us was. I could start storing individual essences, I just need a larger databank than what I have to work with right now.
But I think we can get arrivals down to at least the right universe - at least, the ones we have currently present right now. I can help get the old system you're working on running, if you want another pair of hands there. At least until we figure out something better.