Individualise Offline Files for each account

I've just started using Offline Files and so far found that whatever is made
available offline in one account is available in the others - even though
Offline Files settings (i.e when to sync) are individual for each account.
Surely each account user should select what they wish to be made available
offline?

I also want to know how to prevent certain accounts from using Offline Files
altogether, as well as from accessing my home network.