I’m not sure this solves the problem at all. Isn’t that just forcing clients to switch from relay to relay that doesn’t yet have spam?

Let’s use WoT and for whoever isn’t in it, you need some minimal PoW if you want your post seen… spammers will need to spend a lot of energy for their many posts but for a single user the energy will be minimal.

Don’t want to spend cpu cycles? zap the OP and your replies become visible. 🤷