Are there any significant plans for the mod, or is it primarily in maintenance mode? I'm asking because it seems there are major features running which still do not make the factions in the game behave as in a 4X game. I'm not referring to the player-centric view and the player fleet being the only possible point of focus; I'm fine with that, and Starsector should remain Starsector in that regard. I'm talking about the fact that most of the fleets generated by the AIs are very loosely tied to actual assets. I would expect at some point that (just as a crude example that would need to be refined) planets, depending on their infrastructure, would generate ships or ship parts, assembled into fleets and either stored on the planet or put in orbit for missions or patrols. However, we know this is not the case in the game; 99% of the ships are generated from thin air (or void). Another example is the indestructibility of stations. Under some very specific circumstances, choices, or hard constraints, it should be possible to destroy a station (the AI would do that too).
So Nexerelin makes SS a 4X in the sense planets can be conquered, but the whole economy and military production is still very much like in a RPG (or Rimworld, Story-generator). Stuff is generated when needed, to make a good story, and that's it.
To answer the opening question: I do have some plans for the mod, some that might actually get done in the near future, some that are "yeah, maybe someday".
The game's economic systems are something I've put a bit of thought into over the years; brief comments in the section below.
NPC faction economiesI have a functional implementation of faction resource pools that are expended for actions in space (generated based on the faction's commodity availability in supplies, ship parts & weapons, and fuel) and ground (supplies, marines, fuel). But then I realized the existing invasion points work the same (in a cruder way) while also having far more playtesting behind the system, so for now I'm just plugging a couple more things into the invasion points mechanic, most recently the base strike missions against pirate/Pather bases. Maybe I'll rename them to 'military assets' or somesuch.
A significant limitation is that I have/can only hook (a portion of) Nex mechanics into the system, most notably invasion/raid fleets. Vanilla fleets like patrols and the colony crisis fleets currently aren't connected to it; I might find a way to do so if/when I want, but it'll need a bunch of thinking over and implementation work that I won't get into here.
In any case I don't yet plan on tracking these resources per-market or implementing them as an actual commodity that gets moved around by trade fleets.
There are any number of cool ideas for economic simulation I can come up with, but if the player doesn't actually perceive a difference in how things behave, then the 'fake' behaviors would've worked just as well. (This was a big concern of mine when developing the strategic AI: whether the super smart and sophisticated system ends up playing in the same manner as the crude 'do things at random' system.)
Destroying stationsWell, is there a particular reason to implement this for either the player or NPCs, beyond the already-extant sat bomb mechanic?