What happened to ZBD Social, the first and only outbox-model-on-the-server Nostr semi-closed-but-actually-open social network platform: https://blog.zbd.gg/what-happened-to-zbd-social/ (I just found this post by chance).
I still think doing something like ZBD Social is a good idea if you want to inject some forms of social component into a closed platform. Much better than trying to create a social network from the complete zero. In the case of ZBD I think the biggest problem was that their service attracts spammers and low-quality people by its very nature, so that poisoned the social aspect of it way too much. Otherwise it would have been the first actual "relay community" of Nostr, writable from the inside, accessible from the outside, and automatically filtered to only have the posts from that community (that turned out to be a community of spammers).
Arguably an integration like ZBD Social was what minds.com should have done when they were interested in Nostr in 2022.
It is also similar to what Ditto should do (and what I thought Ditto was going to do).
See also: nostr:naddr1qqyxgvek8qmryc3eqyghwumn8ghj7enfv96x5ctx9e3k7mgzyqalp33lewf5vdq847t6te0wvnags0gs0mu72kz8938tn24wlfze6qcyqqq823chekfst