The desktop experience of clicking the drop down is not fantastic: no tooltips and no real explanation of what clicking the empty boxes does.

yeah, it's the primary reason I still use the (undeveloped) uMatrix. ublock supposedly can do the same things, but umatrix has an amazing interface that's clear and straightforward while ublock is like one of those mobile first (but also only) websites

And you have to actually click submenus to expand them, you don't just hover. And of course other menus like bookmarks open submenus when you hover, so it's a gamble every time.