Thinking about this more, I would like to see an overhaul of how officers get assigned. Currently, the auto-assign for general (non-fighter, non-survey) ships only applies to officers with a crew training rating. I'd like to be able to choose to assign officers who don't, to allow them to gain experience, and potentially a training rating.
But we can go further than that, in a way that ties in with the OP. I propose we divide officers (of all ranks) into three basic groups. Let's call them Elite, Regular, and Lower. For normal ships, Lower covers everyone who doesn't have a training rating. I'm not sure where the boundary between Elite and Regular falls. Maybe the top 25% of officers of a given type. Similar metrics for fighters and survey ships. You can set which pool a given ship will draw from. For instance, you might decide that your older survey ships will only get Regular officers, saving the Elites for the new ships you've got under construction. The same goes for setting it so only Lowers end up with freighters. That benefits everyone. There's a small risk of aging-out your best officers, but it would make things more interesting.