Firefox already start to publish the tab grouping or tab container. User will be able to organize the Tab group for example Shopping,Personal and etc. Lets say you open Amazon and Ebay, User can move this two tab into Shopping container to be referred later.
My idea is, please do the same for BOOKMARK. At the moment, user only have 3 choices. Bookmark Toolbar, Bookmark Menu, Other Bookmark and user can add on addition folder later. But it was quite a hassle to choose the link you want to open especially when the Bookmark Toolbar already fully occupied or you can scroll to bookmark - manage bookmark - and choose the folder. User normally will just scroll to the Bookmark and select from the Recent Bookmark. It will be easier.
If Firefox Developer can let the user to do some BOOKMARK GROUPING or BOOKMARK CONTAINER on Recent Bookmark area, we can just scroll to the Bookmark section, and click the WORK bookmark to see all the saved link for work purposes and ignore other links such as shopping website link. It will be so convenient to have this features.
WORK BOOKMARK for all work related link (saved by user), SHOPPING BOOKMARK for all shopping website (saved by user), PERSONAL WEBSITE for private website such as Netflix etc or Home Wifi Configurations etc (saved by user)