I added a Xylophone to Percussionist 1, changed the name to metal objects, changed the clef, changed the key signature and connected that instrument to the VST instrument of my choice.
Is there a way I can easily add that same instrument to the other three percussionists?
You can at least duplicate Players… then you can drag the custom instrument from each of those duplicates into each of the other percussionists and then delete the temporary duplicate players…