The selling point of Ice (the underlying framework for libcosmic) is the cross-platform compatibility. Can I use libcosmic cross-plat as well, or is it more a specialisation of Ice for Linux with the clear focus on the Cosmic desktop? Would be cool to re-use some widget etc.

What is missing in the existing ones?

Never used bstr. What was interesting about it?

That worked! Thank you! The trick is really to embed the bookmarks into each other :)

Thanks for the reply. When I disable the toolbar, the bookmarks are correctly placed in a folder but the folder is not visible in the toolbar anymore. So I can either have the bookmarks separately in the toolbar, or in a folder but not in the toolbar. The combination of both seems to be only possible if I move the bookmarks by hand in the UI :/