So, this would be like the Hide Empty Staves setting, but would only hide the staves if the entire group was empty… so, like, if ANY woodwind was playing, it would show all woodwind staves. The idea is to save paper when entire sections aren’t playing (imagine a section of an orchestral work with only the strings playing, like the start of most Shota symphonies)… but being easier to work with because the number of staves in each section wouldn’t vary… you’d always show all 5 string staves, even if the violas are resting or whatever.
Cool idea, although for woodwinds there is the distinction between “core” instruments and auxiliaries—you’d want to show just the standard 2.2.2.2 and omit the cor anglais which only does featured solos, for example. To be honest, just a “Staff visibility” signpost would do the trick in a simpler and more predictable fashion.