As promised in this thread, we just released a free demo showing how you can use substances to let players customize characters or others assets through substance parameters.
The project contains a basic character creation scene, along with the scripts allowing you to expose parameters in a nice custom GUI scheme.
We also added the sources of the substances used on the character to help people get started with Substance Designer and create their own customizable assets.
I’ll be checking this out when I get home from work.