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I rendered the terrain parts twice, once with sharp antialiasing(Catmull-Rom) and once with soft antialiasing(Cubic B-Spline). I postworked these two together, erasing the soft layer from the front and leaving it in the distance/horizon. Nice contrast.
The upper sky was rendered separately using sharp AA for the stars. This was then postworked together aswell.
There's some sky-banding in the upper half that I couldn't get rid of.

This beta is great(to a point.

)! I can control exactly where stars appear in the sky now by painting a mask onto the background sphere.
Before, my stars showed up in places they shouldn't have, like around the very bright sun etc. A MASSIVE brush with HUGE falloff makes a nice blend shader.
There's about 60 minutes rendering in total on 1 core. Not too shabby for a quickie!
Thanks for looking!