Forgive me if I misunderstand the problem, but is it not sufficient to implement a fast shouldComponentUpdate on C, ideally making C a pure component? The render pass will still do a check for every C whenever B updates, but I would think that strict equality checks would usually be fast enough even for thousands of components every animation frame.

If that’s not fast enough, perhaps it would be faster to directly subscribe each instance of C to its state updates with something like Redux’ connect HOC. I assume that React does something like marking branches of the component tree as dirty and only doing a render pass on the dirty sections, but I could be wrong. If I’m correct, that would give you direct rerenders of the individual deeply nested C instances without rerendering A or B or unchanged C components at all.