The problem with the Chinese firewall is not a technical one. Fundamentally if you have to let a community know a secret (psst! we are running nostr on IP X.Y.Z.W port M) and that community is infiltrated with a CCP member, they will know about it and shut it down. And the fundamental problem of identifying outsiders/infiltrators and keeping them out of a community is unsolved and probably unsolvable. So as long as there are enough CCP people looking for holes in the firewall, holes will only last for a limited amount of time. This can't be changed on a technology level, not with cryptography, not with anything.