Hi

With Firefox Sync there is no primary sync source. The Sync service will sync multiple devices so that they all have the latest bookmarks, passwords and other data across all devices.

Thank you for explaining there is no master single sourced administration sourced sync access. The problem is several isolated remote conections update al other remote isolated connections with personal private password and bookmark additions of a single isolated remote user connected to sync. A dedicated MASTER sync administered source is what would isolate remote personal private password and bookmarks from acces by other isolated remote sync users connections working inside as a networked group

As I mentioned above, there is no primary device in Firefox Sync, but you can turn off and on various data types to sync from a particular device in that devices Firefox Sync settings.