Deriving subscribed behaviour from Context or event emitter

[oblador]

I was really happy to see subscribed option being merged which helps a lot for react-native use cases – thanks a bunch!

I've been starting to implement it in my fairly large and complex app. It's fine to do on a few select hooks, but applying it to all is both quite cumbersome and cause a lot of unnecessary re-renders for my recently unfocused screen (which is the opposite of what I'm trying to achieve).

Looking at Legend State, they are using a context provider with an imperative API, which is precisely what I want to make it maximally performant. Would you be up for something like this? Happy to send a PR 👍