So, there are exactly million ways one can change how a scene looks in terms of brightness inside UE4. (and million and one ways to go crazy doing it as I found out)
What is the right approach to it? The correct way to setup light and material for values which work in all light scenarios, from the very start.
NOTE: I’m using this PostProcess for toonish kinda looksy
Roughly follow PBR guidelines. Even if you are using a stylized look, try to keep material values close to real world values. You can push them a bit, but not too much. Especially with the base color, use the range from fresh asphalt at 0.02 to snow at 0.8.
Second, I’d set my eye adaption to a fix value and do the lighting.
Then post processing/LUT.
And finally turn back on the eye adaption and mess with auto exposure and using post processing volumes to help control it if needed.