I’m using rate limiting with a burst limit for now. That allows for posting multiple chained events over a shorter period, but also caps out at the same max events/minute, etc.

I think there are two kinds of rate limiting for publishing events. One is perhaps IP based (often unique pubkey flooding), but if other relays or users broadcast/push events that may need higher limits. Another is author/pubkey based, but again hydrating backed up events would trigger this.

Another issue is PoW requirements could be different per relay at that point in time. It’s easy to broadcast to many and have some some work. It’s a tricky problem all round.

Honest Nostr clients should use an outbox system anyway (perhaps with per relay success tracking), so rate limits should just be a delay to eventual posting.