I’ve discovered that if you turn on staff hiding, then a Divisi label will force the stave(s) to show. This is true even for the first system.
So, for instance: I have a multi-flow work for choir and orchestra. The choir is SATB in some flows, and SSAATTBB in others. I’ve used Divisi. However, in the vocal score, I want to hide the vocal staves from the start, for a lengthy instrumental introduction, and then add the choir on the 4th system or so.
Can it be done? I could use separate Players for the 8-part choir, though I tend to get into numbering problems (e.g. “Soprano 1” when only 1 Sop staff = tutti Sops).