Hello, Dave Hilowitz use "modVolume" on group in his preset "Dave Choir". This is a critical parameter which setup the initial volume for each group, allowing later to crossfade with CC. Without it, all layers can be ear at startup.
Of coures, as soon as we use CC, the groups volume start to be properly computed.
this "modVolume" is undocumented, and there is zero trace of it on the internet. I guess nobody is awware of it. It would be nice to put it in the documentation.