I was thinking of using one table packed with all a player’s data and saving it in a single datastore, so that when that player leaves I’m only sending a single save request, and when that player joins back I’d just unpack their data.
Not only would the player basically never lose their data (because if the save request fails, I can send another request like 30 more times or something like that) but I could also auto-save a lot more frequently, but I need to know whether the size of data being saved to a datastore has an impact on its success or not in order for this to actually be beneficial.
have you checked out the published datastore limits.
I ask as it is my understanding that if you exceed them your process will fail.
If its a case of performance then using a single table is better for performance than multiple for which multiple calls would be required.