Saved game limitations in Google Play Games

Question

I have an app connected to Firebase. Users can login with Google and Facebook and create lists of words. I'd like to have some achievements and leaderboards and if it's possible use this to avoid extra authentication methods making the process faster for the user.

• What's the limitation for Google Play Games when saving data?
• Can I save as many lists as I want?
• Could this info be shared? (not really necessary)
• What's the best way when saving info? Save everything together as a big object? Or separate this into pieces (if so, how many slots do we get?)? For example, considering I have 3 lists:

A)

SaveGame.saveGame(data: list1, name: "list1");
SaveGame.saveGame(data: list2, name: "list2");
SaveGame.saveGame(data: list3, name: "list3");

B)

final List<List> lists = [list1, list2, list3];
SaveGame.saveGame(data: jsonEncode(lists), name: "lists");