Nice think about Nostr is it is entirely permissionless. I've gotten really blackpilled on the Urbit naming/network system lately. It goes against my cypherpunk instincts. 
That said, I'm excited to hear about the plans to rip out Azimuth as a standalone protocol. Urbit without Azimuth (and without Ames) is closer to where we are headed with Pallas https://github.com/operating-function/pallas