I know that if I create a custom VSS template with my own material zones, then bring up your prop and load my template (mt6) on top of it, Poser informs me that I'm about to add materials that don't exist in the original.

That's for a prop.

For a character, it seems odd that you can create new material zones with the grouping tool but can only save them to a cr2. Not very user-friend or commerce-friendly.

I'll research this further and let you know how I get on. Thanks for your answers, both of you: you've given me some ideas.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks