Gzuuus on Nostr: This is interesting for specific use cases. Have you read the nostr state machines I ...

This is interesting for specific use cases. Have you read the nostr state machines I wrote some time ago? It uses dag as you mentioned
https://gitworkshop.dev/npub1gzuushllat7pet0ccv9yuhygvc8ldeyhrgxuwg744dn5khnpk3gs3ea5ds/relay.ngit.dev/nsm/tree/master/state-machines-on-nostr.md

Also have you checked cordn by Besao (nprofile…m8px) ? It solves that problem but for mls over nostr which requires strong ordering. In any case you don't need an special relay for this, a cvm acting as ordering oracle gives you that without deployment complexity