Are you using a monitor or VR? I'm assuming a monitor so you may want to try using the Windows10 display calibration tool to make sure your monitor settings are giving you the best / most accurate image possible (enter 'calibration' in WIn10 search box).
I just checked FS2 on my monitor at 30,000 ft over Key West and the sky looks blue, not dark / space-like.
I agree, it would be nice if the transition was smoother. Here's the best I could do to match that window photo using the FS2 cloud and visibility sliders ...
On that picture you can see it very clearly which is why I ask IPACS to lighten up the blue color at those cruising altitudes 
Has this been acknowledged by the devs?
Yes it has. It's going to be some time still before we can address this.
That is no problem, just to know that its on the list
It is something that we know needs to me accomplished.
