moving an inner stave when empty staves are hidden

When empty staves are hidden and “Allow individual staves of multi-staff instruments to be hidden” is selected in Setup preferences - I cannot move the inner staves of a piano grand staff individually in Engrave mode. When I click on any of the inner/smaller Staff Spacing boxes they are all selected at the same time. And all of them move at the same time.

I can select each inner stave box and move them individually if I deselect the hide multi-staff option.

Is this a bug or a feature?

It’s a limitation, certainly, and it’s something we hope to improve in future.

Thank you - hoping it will be soon improved.