Hey! So moon on which Subnautica 2 takes place is named Proteus, however this name is already used by other stellar object; Proteus is a moon of Neptune, which is also known as Neptune VIII, its second biggest satelite of Neptune. So I’d highly recommend changing the name to something else.
And another nitpick, regarding skybox and lighting. So Proteus seems to orbit a binary star system, however said stars are static on the skybox, they always have same configuration no matter what. And in real life, binary stars usually eclipse one another, depending on their orbit, so that could be a fun thing to see in game. And it would allow for pretty visuals, like light on the moon changing color depending on if there is star eclipse or not.
And another, minor thing! Since our moon orbits a gas giant, there would be huge chance that other moons would be here, so seeing those other moons on skybox could be pretty nice looking detail. Oh, and it allows for some worldbuilding aspect going on to it, like ancient civilization using moon configuration to their calculations, or stuff like that.
Hopefully my feedback will be considered, and might be useful, can’t wait to see more from Subnautica 2 world :)