instruments for file and for sections

Hi all,
Frequently, and particularly for the Conservatoire exercises, I use Musescore to write various, let's call it "partitions", that are actually short exercises containing few measures that may involve different instruments.
I keep them in the same file because of some specific criteria connecting them.
I separate one exercise from the other by using "section breaks".
I insert all the instruments involved and I check the "Hide empty staves" in order to show only the instruments in use for the specific exercise.
Unfortunately in certain situations I need to show specific instruments, even if not used, only for specific exercise and I don't know how to do it.
Is there a way to specify for each section it's own instruments instead of instruments for the file?
Thanks,