… tried to create a cutaway score, but even if I redefined the existing staff style to display staff names, they disappear …

For that you need a custom staff style (rather than the Cutaway style), namely a “Display only Staff Name” staff style.

… no way to display multiple empty measures in a row for all instruments (ie, "tacet") … with the staff style for cutaway scores …

I am afraid I do not understand.

Cutaway does not display measures at all (neither empty measures nor non-empty measures.

… or multimeasure rests with the staff style for cutaway scores …

This is really confusing.

Multimeasure rests are in the parts.

Cutaway is in the score.

Are you talking about parts, or about the score?

Thanks Peter-sorry I neglected to provide a screen shot. In the attached image, I did create a style that hides staff lines but displays the instrument name, which works for the first measure (I have a measure of rest to start and end all my works; it's a Quaker thing). But in mm 9-10, having a cutaway style loses the fact that these are two measures of tacet. As I think of it, I might try to have a cutaway style that includes barlines. 

That did it! Problem solved. Thanks!