Rated 4 out of 5 stars
Good Add-on, but I recommend making the hover area a little bit bigger so that we don't have to precisely hover over the tiny area above where the bookmarks used to be. I dont know anything about developing, but maybe replace the bookmarks bar when hidden with a short strip. It reduces the amount of space gained by hiding the bar, but with a little size tweaking the trade-off may be worth it. If you can fix that issue I would definitely give this 5 stars.
I am using classic compact and I have no problem with compatibility.