What works well in these types of games can be pretty simple. You don't need in depth interaction. Did you ever play Escape Velocity or Endless Sky?
It's just a sequence of quests framed by text dialogues with some forks that branch into different missions that aren't too complex: kill such and such, escort so and so, survey something, capture something Nicely written text interaction that isn't too pretentious and helps bring the world alive. A choose your own adventure that can quickly recede into the background when you feel like mindlessly blasting things.
At the end of it, maybe you get a fancy modspec unlocked, or a really rare ship, or a planet switches allegiance, or a station is destroyed, so the player feels like they're having an impact on the game universe.
That's all. It's not much, but it really fleshes out the world.
If Histidine's thing works with the current release I'll try it.
That "That's all" doesn't begin to describe the inordinate amount of work it represent to create in Starsector, plus several of them aren't possible yet. Plus, missions are something that was planned for a long time in vanilla and modders didn't wanted to spend hundreds upon hundreds hours of work on something that could very well become obsolete the next release.
The main issue with these type of simple missions is that you can't have just a handful of them, otherwise people will get bored fast. You either need to write dozens upon dozens of them for every fleet composition / player level imaginable, or go full fledged procedural story generator. It is not something you whip up during a boring weekend.
Heck I postponed Seeker for two years despite having a dozen of extremely scripted artifacts, fully implemented, completely weird, with interesting stories and quests attached to them sitting on my hard-drive because it is beyond my competences to implement the dialogues properly.
There are maybe four or five people on this forum, including Alex, that can properly read, understand and write quests. Unless Alex has some kind of tool to translate them from human code into machine code, I have no idea how he can do that for anything more than basic station interaction.
I invite you to open that file and see for yourself. After all, modding is open to everyone, if you don't like the lack of quest mods you can fix that!