Well, I don't like the actual approach by egosoft neither. I think they want so much to have a special niche, which I can understand, to push a lot on the strategy part and economy simulation, while keeping a good space-ship simulator (after modding , but the physics are there).
Risk is, in so doing, that some of the parts are not so good. Exploration is not, space travel neither. Anyway their unique atmosphere is what made us play all of their iterations. It went somehow partially lost in X4.
Ziplock you should write down exactly what planets, the orbital ones? I can see to make a better use of materials, maybe less clouds. I used more clouds to cover the inherently bad looking terrain tech which is simply the same alpha repeated more times on a bigger sphere. That's why I used a totally different approach for "my" planets that you can fly to, from high to low orbit. They are smaller, much smaller (actually, the Earth's size), but use old style textures, not generic alphas of terrain patches.
The human eye can immediately see if something is a repeated patch or a picture (texture). So the old textures look better even at close inspection (I played a lot with the shades). So in President's End, f.i., the planet looks cool from far or from close orbit. But textures are not big. There is a reason why some hardcore simulators such as Orbiter used tons of textures instead of the nowaday common procedural generation of terrains (and planets). The latter looks fake, you see that it is a generic terrain, even if its normal maps look better. Procedurally generated surfaces on contrary would work very well for small moons or big asteroids, where you can land to mine resources. Hope Ego will add some in the future (not planets, only big roids and small moons), they'd make a lot of sense for the actual game and add a lot of exploration feeling.
Since Orbiter is mostly based on our solar system, we would immediately lose immersion by a procedurally generated Earth. Oc since orbiter is an atmosphere-entry simulator, the textures it uses are massive, with many lods (layers) of more detail textures (12-14 if I remember), while in X game you don't need that. A big texture with enough mipmaps is more than enough. This is to say that, for planets, plain textures still rock instead of other solutions, and any modern gf card can manage them very well.
With those such as Heretic's End, I used other approaches, such as making water planets out of generic planets. The planetary tech is very nice for clouds and climates (in the generic planets, not the orbital ones) but as soon as you see a landmass you catch the repeated generic patch and the passage between land and water is very very bad. There is no overlapping nor tone blurring. Old X3 planets looked better in that by simply using water textures with alphas for the terrain. Their seas were very nice looking, the shores looked real. In X4 the shores are so terrible to make the planets look worse even if all other renderings (clouds, climates, atmosphere) are better. So I used the exchanged planets (such as Argon Prime) elsewhere in other forms, water planets with small isles, only rocky etc.
At the moment I am updating the mods for 6.2, will upload with bug fixs, later on will see the planets.
Btw I was thinking about another optional change, i.e. making highways some kind of "gravity slingshot". The idea is making them very short, but many and pointing to various directions. You manually enter there and when exiting from the exit gate (not leaving midway), the ship keeps momentum. So you can for instance accelerate to 50 km/s and keep going. While normal travel drive is limited to 10. This oc would work only for the player, the other ships would continue to travel by their own travel engine (m and l ships already do it).