I don't want to sound harsh but I think the last thing players want to see are sideline crap or useless feature creep. Unless you have vast amounts of time and energy, or a professional game dev staff, generally speaking indie devs should focus on doing one thing really really well, as opposed to trying to outdo Stellaris. With that in mind I have some suggestions which I hope would help push this dev's patreon beyond the 2k mark.
In a game like this, the quality of writing, particularly during sex scenes, is hugely important. If you want an example of solid sex interaction dialogue, check out EratohoK, Tales of Androgyny or Degrees of Lewdity. I really do wish that the dev either hires a competent writer to flesh out the dialogue, or puts a lot more time and effort into it himself.
I would also like to see more special characters that can be captured or recruited for your space station, such as a badass Samus Aran type bounty hunter, a galaxy famous celebrity or something like Mass Effect heroines. Right now we have some late game high class additions to your station such as the faction leaders, but it would be nice to keep us occupied with similar pursuits before that late game mark is reached.
The price and quality of the slaves should be intensively overhauled. Right now the best slaves cost only about 10k more than utter garbage ones, which is peanuts, given the game's economy. For example, as of right now you can easily get a fully muscled or 100 intellect slave from the discount bargain bin market. This makes slavery element essentially worthless, with the protagonist feeling more like a chicken farmer than a proper Dark Eldar type slave master. Slaves bought from the elite training facility should go for 100-500k a pop, and "princess/queen" type slaves should be a much, much rarer bounty in planetary raids. In turn, these special slaves should have either perks or abilities that make them stand out from the rest, such as higher skill caps, faster training, or ability to earn many times the amount of credits. In turn the player should be incentivised to oversee the training of these prospective slaves in person, as opposed to sticking them into a milk machine or a fuckbox.
The facial animations and expressions as well as the face meshes and textures could also use significant improvement.
