Essentially ships that we players grow ourselves. Procedurally generated, guided by the player actions, they all would be unique, so even all powerful ship would be a once in lifetime.
feed the right things at the right time, to get the right features. have the embryo in right kind of environment for tweaking to features. Push some feature too hard, and you risk killing the embryo or it fails to develop other features. Using mutages would end up a roll of the dice for the basic multipliers, and you wouldnt be able to see what changed and how you would just see the changes in the rate of development. meaning you might end up having to use 10 times more minerals to get a solid hull, but only a morsel to get insanely strong shields. Faction mutagens would be more predictable.
Like feed it minerals and you develop its hull and armor, feed it PI goods and you develop its shielding and electronics and so on. feed it ice products and you push its cyno capacity wheter for jumping or lighting.
Longer you feed it, bigger it becomes, if you can keep it safe and fed long enough, it could end up as a titan. you fail to feed it properly, it will be a useless titan. Would need to be kept fed while in operation, could die of starvation if not placed in hibernation tank for long term storage. Hibernation tanks would drop if citadel is destroyed. properly fed ships not in a tank would be loyal and warp to a safespot and hide there until picked up. Starved ships would go rogue when dropped from a dead citadel. Bigger the ship more it would take to keep it fed, but also the growth process would have its effect on consumption.