Warpcast

You should be able to tag multiple channels in a post, and mute channels. Then you have both additive and subtractive feed curation. 
Also: subscribe to logical operations of channels (funny AND informative, for example ).

Farcaster

there are 2 LA channels

/la and /los-angeles 

the former is more intuitive + convenient to type, the latter was created first (pre-permissionless) and used most often until /farcon was in LA

should the channels stay separate? merge? how would that work?

imo would prefer 1 channel at this level of qDAU / cast volume

IF channels were more tags than forums, there could be paths to either users or mods choosing to merge a pair of channels. From the user side, it would mean tagging both when tagging either. From the mod side, it would mean deferring your channel to the other.

co founder of @metamask . Making computers behave for us.

IF channels were more tags than forums, there could be paths to either users or mods choosing to merge a pair of channels. From the user side, it would mean tagging both when tagging either. From the mod side, it would mean deferring your channel to the other. https://warpcast.com/ted/0xe46b7902