It seems that @cycle/state was intended to be used once per app, wrapping main. Is that true?
In other words, it seems that @cycle/state does not provide a solution for local state. And I am trying to figure out, whether reusing it inside the hierarchy could provide such a solution.
Is it possible to use it multiple times down the hierarchy for the purpose of local state?
Yes, there is no problem with that as you can use the second argument to specify another name for the second state. In fact this might help you: https://gist.github.com/jvanbruegge/9af17f4f5fca8bb3e6198ebe65afac55