[VolumeMixer] Set as default code will cause apps to start on wrong device instead of current default

[Zren]

https://www.reddit.com/r/kde/comments/5w00dx/is_there_an_easy_way_to_change_between_sound_cards/deal49x/?context=3

1. set mpv to output with device 1
2. close mpv
3. set default output to device 2
4. open video with mpv

It will output on device 1

[AndydeCleyre]

Using mopidy with cantata, where each song comes from a new python process (I think), sometimes a new song will use the configured default output, and sometimes it won't. This happens when using a bluetooth speaker as default.

Is it possible / within-scope to force new processes to use the applet-configured default audio sink?