Is this for modeling a single reaction or chain of reactions? ie you don’t need neighborhoods if you are modeling 7 trillion of one thing combined with 14 trillion of another?
It looks like chains of reactions etc. As you say for something simple you don't need something complex.
It's a DSL for computational biology where very little documentation has apparently made it to a public forum. I can decode the programming language part of it but I'm not up to scratch on computational biology so I'm not sure exactly what they want it for.