I like the way tiny manage this. It underline the first available letter in the channel name and create automatically a shortcut as alt+$letter. It's really specific, but any method is welcome. A fzf-like menu could be cool too.
Just a thought: we could do e.g. alt+shift (hold these keys), then type any letters of the channel (filters the channel list realtime), then when only one is left, release alt+shift to jump to it