First - congratulations! Thanks to hotfix 1 for P3Dv5.1 I decided to drop v4.5 and use v5.1 with Enhanced Atmospheric. It looks and works great!
What I don't like is too dark (and contrasted) virtual cockpit (eg. PMDG 737-800NGXu). I's because of HDR enabled by default with EA set to on.
My suggestion is to make a new slider in HDR settings to control virtual cockpit brightness. I did something like this using Tomatoshade for v4.5 (VC sun diffuse and ambient diffuse). This would be good for developers as well because they won't to have to modify cockpit textures (brighten up or darken) with every platform update.
Have a great day and keep up your amazing work.
Adrian