I took a different approach to this three years ago with multiplextr. Ultimately, someone has to handle the heavy loading stuff, which sort of pushes us towards bluesky's central relay/appview model in terms of censorship. But at least it's optional. The main problem with this is either the client or the relay needs to handle outbox, but not both — people used to put nostr.wine relays in their inbox/outbox relay selections, which just messed everything up.