Oddbean new post about login | logout i think that local relays are great for speed and distributing or broadcasting that content to other relays helps with decentralization. it's a good mix. no one wants a slow website.
I know nostr.band is alreadyacts like a client requesting new events from all known relays. When I post an event to my personal/development relay, it's getting requested and indexed within seconds 😆 So broadcasting content already works in a neat way I must admit even I just broadcast it to one relay.
The outbox model helps here too. I publish to my private relay and it's discovered right away.