APIs for Playlist and Queue in Volumio

I am looking for a solution to get two use cases working for Volumio.
My Volumio has the IR Remote Control plugin and I wolud like to send commands by RC for:

  • Add a playlist to the queue without clearing the queue before and without starting to play.
    I would like to clear the queue with the ClearQueue command from REST API, then add multiple existing playlists with selected tracks from genres to queue and start playing the queue in random mode manaually.
    The “playplaylist&name=” is working fine for playing one playlist, but it is clearing the current queue and it starts playing immediately.

  • Something like addToPlaylist&name=Example to add the current played song to an existing Volumio playlist “Example”
    The benefit would be, that it would be possible to create Playlists for the family members by keys on the rc. Everyone could add the curently played song to the personal playlist if they like it.