Do you have the import/export HTML export option?? - or just back up/ restore?

when you save a copy of any file you still have the original.
So you don't need to do anything with the new saved file unless you need to restore them for some reason.

If you can save the bookmarks in the HTML format - that file when clicked will open in a page and the bookmarks are all fully active - click on one and it opens the web page it points to.


for importing or restoring bookmarks you would open FF and in the organize bookmarks you would click the restore and it will open a box so you can locate the bookmarks.json file and then click it to open - and it will be restored right back in the bookmark section.

So HTML file type is usable, clickable & readable & you can import them to FF also
&
.json file is mostly for restoring the bookmarks back into FF

It won't replace anything inf his saved bookmarks - unless you use the restore or import tool.