You should've stopped right there.
NMS creatures are PG, SCO are not. Let's get that out of the way first, so you're no concerned about seeing ridiculous looking creatures (which was the case with NMS).
NMS planets while repetitive in nature as all things PG are fantastic. The PG variable limits could've been wider to make for example totally flat, caveless planets etc, but I think a lot of planet PG was restrained by gameplay mechanics such as necessary variety of elements (so you don't get stranded or some such) etc. SCO on the other hand, might suffer from the "planet flatness disease", since that's what you want most of your planets to be like, 'cause lander/exploration mechanics. It would be super cool to have a mountainous, maze-like planets where you could only explore in the valleys, but I wouldn't bet my house on it.
My main gripe with NMS planet variety was that most of the planets had their PG variables somewhere in the middle of their range - absolute most (98%) of the planets were hilly, flora and fauna present (80%) and atmosphere color variety was very limited. But, NMS had its moments. Some planets were truly breathtaking looks-wise, the game kept wowing you even after 60-80 hours of play. They were super rare, but unfortunately, in other aspects, there was nothing special about them.
From what I see, SCO has already beat NMS in at least one regard - sand dunes planets. NMS doesn't have have those. 
I urge Stardock to implement as much color variety in planet PG. For example: red, green, blue sand dune planets, monochromatic (grayscale, spectrum scale (rainbow worlds?), any color scale) crystalline planets etc. Use pre-determined color pallets that are known to work well together.
For example, I'd like too see Black/Green mushroom planet(s) with Cyan and Magenta particles floating in the air:

Pink/Brown planets with Baby Blue features like flora snake-like patches/river/lakes. (EDIT: you got that covered with mushroom planet concept)

Etc. etc.
Make those rare and make most of the planets Moon/Mars like (flat, barren, empty) so you don't have to land on every planet in a star system, but star systems don't feel empty.
I was actually more concerned about them having enough manpower when it comes to art and design.
This is something we shouldn't be concerned with TBH. We're not running the business. Just the feedback train.