Is it possible to incrementally update the schema? I may like to develop it over say ten iterations of incremental points that I missed. After each iteration, I want examine the schema, and say what I want changed.

That would be useful for testing MVPs with dummy data to see if they work. However, synthetic data is usually used when you derive new data from existing data, so the new data is called synthetic. From the README I didn't quite catch if that is the case here, but still useful.