Here are some things I think you should be able to adjust in the configs

1. You should be able to control minimum block light and minimum skylight separately

2. For maximum skylight you should be able to adjust the brightness factor per dimension (and maybe even per biome to make some biomes more or less spooky) rather than having to choose between turning off the mod for that dimension or dealing with complete darkness when you're just standing out on the surface

3. For maximum block light there should also be a global brightness factor and a per dimension (and biome if you choose to add that as an option) brightness factor that overrides the global one for that specific dimension