Backup the folders mentioned in the article BEFORE you try this

I logged into a Windows 8.1 Mobile to update it to Windows 10 Mobile, the favourites that was synced to different location at the time were merged into my current 5 x Windows 10 Edge Browsers and my Microsoft Lumia 950 .  Not good as my current links had been sorted and cleaned up, so I reverted to my backup.  The location that I had backed up was:

%LOCALAPPDATA%\Packages\Microsoft.MicrosoftEdge_8wekyb3d8bbwe\AC\MicrosoftEdge\User\Default\DataStore\Data\nouser1\120712-0049

This contains the folders:

DBStore
Favorites

Restoring these folders did put my favourites to where they were before I logged onto the Windows Phone 8.1, BUT as soon as the favourites synced, after a few minutes and a few restarts of Edge, the old favourites were back.

Upon investigation I noticed that my favourites were also in the folder below, in .JSON format:

%LOCALAPPDATA%\Packages\Microsoft.MicrosoftEdge_8wekyb3d8bbwe\RoamingState

As I had nothing to lose as i had a backup, I deleted all the .JSON files.  This reset my favourites to default of nothing when I restarted Edge (the spartan.edb in DBStore was default 2048KB), not what I wanted. I also tried restore the DBStore & Favourites folder again, but all the older favourites came back again.

I then deleted the .JSON files which were dated just after I logged onto the Windows Phone 8.1, there was about 1800 of them, with nearly all the same time of just a couple of seconds between them. I deleted the DBStore and Favourites folder and restored the backed up versions again.  This time when I restarted all my Favourites were back as they should be and all my others computers and Microsoft 950 synced back to this version.

So it appears that to restore Edge Favourites to a point in time, it is important to backup both locations, not just the first one in the list below:

%LOCALAPPDATA%\Packages\Microsoft.MicrosoftEdge_8wekyb3d8bbwe\AC\MicrosoftEdge\User\Default\DataStore\Data\nouser1\120712-0049

%LOCALAPPDATA%\Packages\Microsoft.MicrosoftEdge_8wekyb3d8bbwe\RoamingState