Hopefully the question summarises adequately. Since FF56 any add-on that had this (what I consider) essential function has ceased to work, with no plans to update. The functionality to keep a Live Bookmark open whilst middle-clicking multiple articles was a massive time-saver and was one of the things that kept me with FF for well over a decade. Now it is gone, please is there any way to replicate using about:config?

Any assistance hugely appreciated.