Nested data sets (at least if I understand you correctly) do have their place. For example, let’s say you want to have a multi-user repository for TimeMachine backups yet the convenience of being able to back them up in one go. Well, a nested data set makes that possible - each user gets a share consisting of a sub directory within a top level share that is only accessible to the admin.
With access based enumeration, encryption, and no browsable TimeMachine shares (once they have been set up), there is also minimal risk with folk being able to mess each other’s shares up. But in this example, there is only one user conducting top-level backups.
Yet there always is the risk that any time machine activity during the backup will toast the integrity of said backup. So ideally, restrict the time machine backups to a window when the top level is not backing up. That way, everything can coexist peacefully.