Good workaround for firefox's horribly-misconceived addon bar! Rated 5 out of 5 stars
Firefox inexplicably has an addon bar that (1) takes up the entire width of the screen even if there's almost nothing on it, (2) neither the bar nor most of its icons can be moved from the bottom of the screen, and (3) can only be shown or hidden so that none of the information on it is visible. Barlesque addresses (1) and to some extent (3) pretty well.
UI Fixer (or Mar Mod Updated) can address (2) by allowing you to drag the addon-bar-only group of icons to another toolbar. Alternatively, url-addon-bar moves the *entire* addon-bar inside the right-hand side of the address/location bar. See my collection https://addons.mozilla.org/en-US/firefox/collections/dabruro/compact/ for additional comments.
When minimized, Barlesque seems to auto-show when some of the icons or information on it change, though I don't think this is 100% consistent. Another reviewer mentioned that it auto-shows when changing tabs -- that's true although I think it *should* do that if changing tabs causes any change to what's shown on the bar.
As pointed out by hermandes, it would be very nice if Barlesque had the ability to auto-show (temporarily) when it's minimized and we hover down there in the corner, so we don't have to click to show and then click again separately to re-minimize it.