I have a confession to make! I uploaded a new version 3.1.0 of the shaders to avsim library and made a mistake which weakens the cockpit shadows. I have uploaded a corrected version 3.1.1 but last time I looked it wasn’t ready for download. Apologies to anyone who downloaded the earlier version.
The 3.1.x release fixes the sunlit roof that I previously described
Here is a before and after with the original FSX shaders and version 3.1.1
ORIGINAL – Note the top of the seat belt is sunny and that the top of the far wall is sunlit too.