ChatGPT / LLM type tech could probably be effective in grouping people into relays.  it should be easy to identify Bitcoiners, Nazis etc.

take the 10 most prominent members of each group, train the model on them and it will find all the other group members.  then put them all on same relay.

or for a more sophisticated system it would be able to define groups by itself.  maybe you would end up getting grouped based on your IQ or age rather than your interests or politics.

there are billions of people but our brains are wired for a social circle of only about 100 people and that is reflected in the patterns of people following each other online.  we need to mirror this in how relays work and LLMs can automate this and make it efficient.