I may well be missing something,
but the only way to ad a bookmark to a sub-folder seems to be to D&D it to the to plevel, adn then do a multi-step move to a sub-folder.
Is this right?
If so, it is very inconvenient, enough to make the tools non-usable. (for me).
Generally all bookmarks are hierarchically organized, and this seems like a basic feature.
(Is this project still alive?)