Hi,
Glad you liked the demo, it is a GPL project at
https://github.com/zubairq/coils.
I may have fixed the bug with going back in time, not 100% sure though, but maybe try it again as more fixes have gone in.
Regarding how people are storing data for react, this is a big topic in itself. I personally (and with Coils) keep a UI only data structure which updates the React GUI, and then synchronise the state from a Data store totally independantly, although I have seen that other projects mix this up a bit, or don't give an opinion on it, which can caue misuse. Does that answer the question?