As you said that I was wondering whether the #GFC admins have figured out how to block #nostr  #relays by protocol behavior as they've done with #signal.  

From what I've read it depends how simple the protocol is. #xmpp  is hard to block even for China because it's so simple, but most others are a done deal already. 

 nostr is extremely simple. It's all just json being passed around websockets 

 but it's encrypted from client to relay. 

 Not always but I don't think that matters