Created attachment 7085 patch A concrete case is the use of a Bluetooth headset. On connexion, the headset become the default output, with a different volume value. Press a volume key was causing a volume change from the last value known by this plugin (the volume of the the previous output).
Thank you. Pushed to git master. Please let me know if you find more issues with bluetooth headsets. Patches welcome. If you would like to make more contributions please contact me on irc (#xfce-dev).