Is it possible to change to a Player’s other instrument without switching to Galley View?
Not in general, no, because you have to create notes on that instrument. If there’s no music at all yet, then dragging the order of the instruments in the player’s card in Setup mode will change which instrument is shown, but again, only if there’s no music.
OK. I’m using instrument changes as a way of changing the Staff Labels for a Solo Player in one Flow.