Wait there's no goddamn way they made the client figure out where to put notes. The Outbox relays are where you put notes. You have to be wrong. If not, what the fuck are Amethyst and nostr devs even doing?! An aggregator/proxy relay can be added to make the client more efficient as regards fetching notes. If I am not mistaken, the aggregator itself requests notes and makes copies of them. Relay to relay. I use one. The aggregators can themselves use the Outbox model to ensure it fetches all the right notes. And I thought they used published Outboxes in Outbox model, on a nostr event that describes your Outboxes, not info from the client.