Daniel, that’s an explanation I can get my head around. Thanks!
I understand that, for now, the player’s music will have to go for technical reasons, BUT I think it would preferable if it was merely hidden, so that it would be possible to get the music back. After all, composers change their minds all the time… 
Now that I got my head around this, more or less, I can say with a certain amount of confidence 
Make sure a layout is selected, then use the checkboxes either in the Flow panel or in the Players panel to hide the player from the selected layout. If you use the Flow panel checkbox, the operation will include all the checked players, conversely, to remove individual players from the layout uncheck a player.
Now, nothing is deleted.