This is very cool, but it seems extraordinarily cumbersome to pass on the generated super long string to another computer or mobile device.
An improvement could be to reversibly derive a few random words ('what 3 words' style) from the public key I suppose - so that it can be easily shared over a voice call, or to make it easier for the same person to enter on another device.
In this case the 'server' is up for an extended period of time, presumably, and the public key is both the address and authentication (unless you turn on requiring a specific key on the initiator, I think? I only glanced at the docs.)
With enough nodes you'd end up with multiple nodes having the same words (divide the possible keyspace by the possible combination of words and you'll get a very large number), and also you'd be at significant risk of people finding nodes just by banging away trying to connect to different 3-word addresses.
I agree that the tool seems to be intended for same-party use.
The protocol team is looking at using the ristretto algorithms to derive “subdomains” which would reduce the amount of key sharing a fair bit