I love this feature and to my eye brain it looks correct and it adds to the immersion.
I think the problem is that our eyes acclimate like this almost automatically with very small eye movements and is virtually undetectable. In Trackir and mousing, I have to pan and zoom with purpose and be deliberate about making the right light setting happen. So this game has taken an involuntary automatic reaction and turned it into a physical control that takes an effort… and that’s why the brain something something and yes I agree an on off button would please everyone except for the folks that don’t like either setting or for the folks that like the way DCS does it and then there will be other folks that still can’t fly anyway.