I'd like to see them sitting in the seat if assigned, I know they don't do much but still... Flying the SLF for me has been invaluable and it seems a bit mean they are consigned to invisibility.
Sure there are lots of things to expand on from there, I'd
love to see that, but in the meantime just seeing them would be nice
Things to add:
Recovery missions on ship destruction.
Revenger against you if you don't recover them after ship destruction but someone else does.
Background story missions.
Advantages to the crew in big ships - perhaps 360 scanning and 2 SLFs being launchable as with MC. For the biggest ship perhaps upping to 3 crew could give you an extra MC extra like pip?
Sending them out in the SRV?
Some RPG light elements, crew maybe can improve scanner range, weapon effectiveness/accuracy, increase reactor output, effect limited repair, etc. Maybe have more specific NPC roles and you can shuffle them around, different NPCs have different capability in roles and can improve.