Maybe some sort of a split zaps model. One portion to PoW to lower surface of spam. The other gets evenly distributed to your connected relays. nostr:npub1rtlqca8r6auyaw5n5h3l5422dm4sry5dzfee4696fqe8s6qgudks7djtfs sort of mentioned something like this. But again. Not the most user friendly and can definitely price out people who can’t or won’t spend their sats.