I see.
Hmm.... it bothers me that when I update the scenario, all existing games using that scenario stay broken because the scenario's control.lua is inside the save game file.
Some parts of BNW are very definitely scenario things. The fact you start with that particular roboport layout and have no character, starting researched technologies, stuff like that. Those are all scenario things.
Others, like the strict controls over what you may have in your inventory. Spilling things on the ground rather than putting them in your inventory when you do things like change recipes in a machine. Those kinds of things are more mod-like behaviors since they involve a persistent change in game mechanics.
I added a mod component to BNW to allow you to have special starting robots that are extra fast. Maybe I should move some of BNW's existing functionality into the mod portion. That would allow me to change them with an update to BNW.