It's looks kinda pretty, but is there really need to use external service to sync bookmarks, when you literally can use internal bookmarks which already synced by Firefox Account. Seems like unnecessary overhead or messing with user's privacy...

The bookmarks either do not show:
https://imgur.com/n8XSAD9

Or only show in one column:
https://imgur.com/1MUNYvK

And I am not able to adjust it.