So, for one thing, I recommend the datastore2 module found here:
As you could probably tell from the description, this module makes sure that player-specific datastores never lose data, and has all kinds of cool functions for setting/saving the data itself.
Answering your question, datastores have throttles to how often you can save something to a datastore. There’s a page on the dev wiki for this. You can either make a custom throttle that denies players from editing the datastore too often, in line with the datastore’s limits, or you could probably save this data to a table that is kept track of in-game, doing both is even better.