There is no command to add or remove Favorite channels by hand or automation.

Eg, To automatically add a channel to one's Favorites after joining and being in a channel for more than an hour. Or right-click popup menu functions for Favoriting channels.
I'd be more apt to use the Favorites feature if I didn't have to manually fuss with them.

Favoriting the current channel on the current server to automatically join next time you reconnect, should be very simple to type in.

/favorite -a -r -j -n -l [#channel [#channel...]] [network [network...]] [-p password] [-f folder] [-d description]

-a add
-r remove
-j join on connect
-n minimize
-l list
#channel(s) -- optional. uses current channel if omitted. allow multiple channels (identified per channel prefix), either space or comma delimited.
network(s) -- optional. uses current network if omitted. allow multiple networks (identified by having no channel prefix), space or comma delimited.
-p password -- channel(s) key.
-f folder -- keep favorite channel(s) tidy in folders.
-d description -- description of channel(s) being added.


/favorite -ajn

* #mIRC added to Favorites (networks: EFNet) (autojoin) (minimized)

Well. At least I won lunch.
Good philosophy, see good in bad, I like!