Temporarily change staff order throughout the piece

I'm working with a professional arranger, and he asked me to always put the lead voice always on top even though it changes frequently during the piece, so that he knows which one he needs to use as a reference in his work.

I think this would be a great feature to make mscore a really professional app, even though it seems really hard to implement at a first a glance, especially when dealing with line breaks. Perhaps the lead voice could be marked as a measure interval, and that would force line breaks at the beginning and at the end.

In the meantime, I'll be happy to hear about a workaround, since I can't think of any. The most obvious one would be renaming the single instrument line, but I don't think it is possible.