How to start the Media-App with a Shell-Command in order to get shuffled replay.
I hope the Media-App support such options.
And another thing is, you can start more than one instance of the Media-App which leads to stopping the replay of the first started instance. Maybe here exists a option too to prevent multiple-instances?
It might be possible through D-Bus. There is a r/w property Shuffle (and things like Play()/Pause() methods exported on the org.mpris.MediaPlayer2.jolla-mediaplayer service.