After playing around a bit more I think I got to something a little closer through some workaround cheats:
Basically, it occurred to me what if I add a spacebar for the player names so they appear “blank”:
And then check this option in the layout preferences to show the now blank player names:
Effectively as a result the names disappear from those staves. Then I selected all these players and combined them into a new player group called PERC. With some adjustments in engraving options to place the group bracket closer to the staves.
Ultimately this gets me pretty close to my intended goal, in terms of functionality. I futzed with the settings for group names, it seems there is no way to orient them horizontally so I could effectively cheat it as a staff label. Ideally, I’d prefer to that, as opposed to the vertical/sideways group label. Curious if anyone has any other thoughts, but I’m glad this gets me a bit closer!
Updated project here if anyone is curious to mess around:
Consolidated Perc Staff v2.dorico (534.7 KB)