The groups of bookmarks REALLY need to be collapsible before I can use it. But when that is fixed it will be a useful replacement for the defunct Bookmarks menu by hatdio.(https://addons.mozilla.org/en-GB/firefox/addon/bookmarks-menu) which I had got so used to.

I understand from elsewhere in he user comments and replies that the collapsibility is coming, Thanks to the author for all the work