I know, that's why I said, that when you hit things like that (state that is too big to pull onto the client at once, and/or displayed at once), React's (and I guess a lot of other immutablity-based frameworks') dataflow management stops being magic, and you have to start tending to it.

Which usually means this model loses all advantages compared to simple MVC, or imperative systems, and at worst, becomes another headache as implementation details start leaking.