hello halmos, in most cases extensions are developed by independent third-party developers & not by mozilla itself. so please directly contact the extension developer through the means provided at the homepage - they can likely give you more detailed guidance and are the only ones who can make adjustments in the addon or incorporate feature requests. thank you...

While there are many aspects of Firefox that you can modify with style rules and other little modifications, the program icon on the dock (or the equivalent on the Windows Task Bar) cannot easily be changed. What I know is in the following thread, which was for the equivalent (much less pretty) version of the feature on Windows: How do I turn off the green download indicator that overlays the taskbar icon.

Note that this is implemented via this bug:

• bug 548763 - Show download progress in app icon in Mac OS X Dock

Please do not comment in bug reports: https://bugzilla.mozilla.org/page.cgi?id=etiquette.html

Sad to hear, but thanks for the reply.