Randomizes recipes (amount of ingredients and products, crafting time) as well as many other things that can be toggled individually like belt speed, crafting speeds, energy consumption, weapon damage...
What do you want to edit? A lot of things can be set up with the ingame mod settings, that's the intended way to configure the mod. Only if you want to do some advanced stuff, like add some entities to the blacklist yourself, then the config file can help with that. If you have more questions about how to do certain things, feel free to ask, it is bit of a mess to be honest.
While going over the code to update the mod for 2.0, found & fixed some issues with the blacklist logic. Maybe this fixed your issue, can't be sure without a way to reproduce it on this machine though.
