Can # channels be advertised or loaded on first repeater connection?
IE: Repeaters all store and share # channel info (however frequently updated). When companion pings the network, the first repeater to get hit sends a hash back to the companion. Hash matches, no need to update. Doesn't match, current list is requested. Then we can all stay off Public a la Brad's FB post.
Update: If one repeater is isolated, it can also request list from Companion that visited 'the mainland'. It already knows if it's isolated b/c it didn't get the updates at 12am/pm. So its list will always be stale. It starts asking for hashes at 12:30am/pm.
Something like that.
Update 2: It probably does NOT make sense for an isolated repeater to have a list of channels that it can't itself reach. It would risk bifurcation or creating a 'sub-channel' that was independent of the original. But I guess that's part of the nature of ephemeral messaging vs. room servers.