More auxiliary command stations, to. . . allow officers to have more extensive career histories:
This has been discussed many times in the past. The main reason cited not to do this is that it doesn't create interesting decisions in most cases.
True enough, however it'd allow for more story opportunities. Having the ship commander separate from the ship's primary function, has potential for story set-ups, whereas the single-officer ship has less. Especially when you factor in the "political reliability" option for promotions.
An officer character who has high combat-related stats, but low political reliability, and they get assigned to a garbage scow for 5 years because of politics, is a prompt for writing a short story.
"Despite graduating at the top of their class at the Academy, Captain Wingus was assigned command of a garbage scow after a falling-out with the Admiralty, not helped by spilling their drink on the Grand Admiral's bosom at a Sector HQ soiree, where they languished for 5 years before acquiring a sufficiently embarrassing amount of seniority that necessitated their transfer back to a ship of the line". Comedy all round.
And it reduces the amount of "dead-end" positions. Like, for terraformer ships, you have the ships, and maybe one staff position, and that's the only use for the whole officer skill bonus for terraforming. Having more positions on ships would help shuffle characters around, provide variety etc.
Sure it wouldn't be "optimal", but it'd be nice for it to be an option. Just like how "realistic promotions" isn't optimal.