How about a hash cash based pow concept where nostritches have to Zap the network or a specific relay or something like that to make a post. Cost to post goes up until spam decreases, almost like a difficulty adjustment. Every action (post, like, repost, etc) all has imbedded zaps. It would also be acceptable for a lower tier, less expensive experience that has more spam but costs less (nothing?). In this way end users can specify how much they want to spend and what they want their experience to be like. Could also provide incentive to run relays.  Market dynamics would reward most freedom, least censorship, best / fastest relay  performance.