I have been using envshade to change the cockpit brightness by reducing the HDR contrast but I believe it is linked with darkness of the night which is reduced as well. I have been playing around with envshade settings but quite unsuccessful so far.

Also, I have been advised to uncheck cockpit receive shadows but it is no so great as I can’t see shadows in the cockpit anymore. 
I know as well that I can manually disable HDR via p3d.cfg, it gives a nice cockpit lighting but also gives a reduced night darkness and p3d rain effects become almost invisible.

would there be a way to decrease night darkness via shadersHLSL perhaps ? 
 

4 hours ago, cmdn said:

would there be a way to decrease night darkness via shadersHLSL perhaps ? 

I think someone asked this before, but it was for a different scenario. In case you're wondering, using TrueSKY will not allow you to change major attributes of the shader, as the files themselves are compiled. 

If you're using the regular lighting, I think there is a way, but it requires significant changes to the HLSL code. P3D uses IBL lighting unlike v4, and now calculates lighting based on the image (in this case I think its the moon / sky texture). Unfortunately it's not like a multiplier anymore like P3Dv4, instead the lighting code is a bit more complicated and might need some changes in either one or multiple files.