Un-/hide empty staves in range

Is it possible to hide/unhide empty staves in a given range of measures instead of just setting this option globally, for the entire piece?

I have a song with two instruments/vocal parts. The main vocals are present during the entire piece, but background vocals only start about half way in. Since I don't want to bloat the score, I have "Hide emtpy staves within systems" checked, so that the empty background vocals aren't shown in first half. This all works great, except one problem:

There are some parts in the second half, where the background vocals pause for a full line worth of measures. On these lines, the background vocals hide again, which is expected, but it is confusing to read since on some lines there are background vocals present, and on others not. Very confusing for the background vocalist, it would be much better to just have the emtpy measures show there.

I would like to be able to say "Hide empty measures of background vocals in the first half, but in the second half keep all measures even if they are empty". Is this possible?

I have tried the various visibility options under Staff/Part-Properties and Measure-Properties, but they don't seem to play well with the global setting. When I try to unhide a measure, by marking it as visible in the Measure-Properties, nothing changes. And if I disable the global option, and try to hide each individual empty measure in the Measure-Properties, the layouting doesn't accomodate, and the lines stay the same height.