Better spam mitigation for replies, like trust scoring or something like that. It's only a matter of time to the next reply guy attack, better to be early.
Discussion
I went over to #Coracle during that whole debacle, until nostr:npub1utx00neqgqln72j22kej3ux7803c2k986henvvha4thuwfkper4s7r50e8 released his WoT relay.
Web-of-Trust or Pagerank (see http://npub.world) based filtering for replies would be a great addition to Primal, especially if the user has the ability to turn it on or off, or even adjust how aggressive it is, in the settings.