When I have a score with multiple staffs and I use the Visibility property 'Top Staff Only', then it's indeed only printed on the top staff, according to the staffs selected in the Page Setup.
But when I use collapsible staves this does not work, if the staff that's really the top staff on the print preview is not the top staff according to the page setup.
Thus my question is : how to accomplish that something is only printed on the staff that's really the top staff?
Create a control staff with the items you always want to see.
Don't collapse it.
You can wish that NoteWorthy would adopt your view of what the 'Top Staff'
really is.
FWIW, I wouldn't count on your wish being fulfilled: