Right, we basically have the same thing with bunkers. "Sign in" to your nip 46 signer once, then authorize sessions with the bunker. One nice thing about this is that the signer and data storage are decoupled, which means you're not limited to the "homeserver" paradigm, giving you lots of options for special-purpose relays (inbox, outbox, DM privacy, topic-based, community relays, trending relays, etc). Twitter has tons of interesting caching mechanisms that allow for content to reach across the network quickly. Home server designs (as I understand them) don't actually work very well for that kind of thing.