Replacement for "Set As Bookmarks Toolbar Folder" - does it exist? If not: can it be made?

Since upgrading to Firefox Quantum, I have been replacing my extensions, and I have generally found equal or better alternatives. However, when it comes to the very simple legacy extension “Set As Bookmarks Toolbar Folder”, I am at a loss.

The extension page is here: https://addons.mozilla.org/en-US/firefox/addon/set-as-bookmarks-toolbar-folde/

What it does is really simple: it makes it possible to choose a different folder for your bookmarks toolbar than the default one. Thus, it becomes possible to have a distinct bookmarks toolbar folder for one or more of your devices, or simply to switch between two sets of bookmarks toolbars. Typically, it is used to separate work and private links.

Does anyone know of any replacement? I have searched high and low, but I might unknowingly a stone unturned…

Or, more fundamentally, if I have to start looking into making an extension like this myself: can such an extension be made using the Quantum API? If yes, could anyone point me in the direction of useful documentation and/or tutorials for making Quantum extensions?

As this is not a feature of Firefox itself and the “Bookmark Toolbar” section is tied to the bookmarks toolbar itself this is not a feature that can just be recreated.

Extensions can’t create toolbars either, meaning you’re limited to the UI elements the API provides you (for now). You could imitate a bookmarks toolbar on a custom new tab page for example, or implement your own bookmarks popup or similar.

It’s a shame that creating additional toolbars is impossible. That would have been an obvious workaround; to hide the default bookmarks toolbar, and then add a toolbar that displays the contents of a specific bookmark folder.

Is there any ETA on when adding toolbars will be made possible with the API?

There’s no ETA yet, but you can track its progress by following this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1215064