It works as expected. It could have an option to set double click speed, though. Could also replace the icons for a single SVG, as the PNG images make up for most of the 17KB of the add-on package. It uses WebExtension technology, what is good in the long run (let us hope there will be no more big changes in the browser pathway for the next decade or so), but it is also its weakness, not working on "about:" tabs, or on "addons.mozilla.org" (why, Mozilla, that's so annoying!) Anyway, good work.