first thing i recommend is to use ProfileStore - Save your player data easy (DataStore Module) if you’re serious about data related stuff
if you’re going todo something thats large in data say 1000 items in an inventory then directly accessing data is way better instead of accessing instances, better for that cause with say 1000 items there might be extra load time if you use instances cause you’re waiting on them to all load
i personally prefer doing instances anyway (more of a preference thing) cause of having folders as the main thing then attributes tied to folders, if you have a loading screen then doing instances doesnt really matter anyways, and one good thing about doing something like instances is that the client can access from anywhere cause its tied to the explorer compared to having to use something like a replicaclient module to access data on the client