I played a bit with it and looked at the code and I wondered about the following:

Would it be possible to replace code like

lightLVL < 0.5

fog > 0

with solutions that can handle smaller increments.

Basically something that looks like a https://en.wikipedia.org/wiki/Sigmoid_function

Where x could be the value (lightLVL or fog) and Y would be the amount of the bonus that is applied at a certain value (so max bonus, as defined in the sandbox options, is applied at lowest light level).

That would allow defining higher bonuses that are applied slowly as the values change to e.g. make zombies almost completely blind at night, while retaining their sight during daytime.