heres a simple case:

you create a team that cares about a hashtag. you create a relay, with them as mods. you publish your nip66 events with the hashtag.

clients offer up these nip66 relays, when following a hashtag, the relays go in the field for relay in the follow list.

mods that browse global of that relay casually can remove offtopic and etc, perform their regular mod duties as they see fit.

done!