Hi Dmytro

Firefox Sync is designed to keep bookmarks, passwords and other data in sync between multiple copies of Firefox. When it does this, it makes sure that the latest data is synced.

There several element is a waypoint between the copies of Firefox that your have connected to Firefox Sync.

I hope that this helps.

Hey Paul, thanks for the reply. However, this doesn't clear up any of my questions or concerns.

Besides, my problem is that there isn't really a clear way for me to make sure that only the latest data is synced. It just syncs whatever the server has onto my device without any way for me to control it besides switching parts on or off. Most importantly, there is no way to undo those changes, unless it's the bookmarks and only the bookmarks.

Why not have the same kind of backup for the rest of the settings or all the other elements you can sync? Or just have one single copy to return to in a case of an unfortunate sync like mine? Better yet, have a way to review the data that's about to be synced?

Even disregarding all these and previous questions, the main thing that makes syncing process a total nightmare is the fact there is no way to clear whatever is currently stored for syncing, unless you count deleting user's account as a solution.

If you use the "forgotten password" option, it will clear what is currently being synced between devices.

Firefox are being deliberately misleading about syncing failure. They refuse to admit that their sync feature simply does not function. As soon as you export and import all your data, its is lost, period. All my extension data was gone. Here is the false explanation Firefox put out, Check Sync Settings >

   Verify Add-ons are Selected: Open the Firefox Menu (☰) > Sync > Ensure that Add-ons is checked

This is total nonsense. There is no such feature for selecting Add-ons or extensions. So, why are Firefox giving false information?