I think the dev should focus on adding more sex positions, different expressions, actual robot having orgasm and not just that heart filling up and doing nothing instead of those little things like cuddling, and other non sex stuff that I'd probably see being added when he expands story and make her feelings actually matter for somethign becasue right now you can't make her happy, in love or hate you, she always lets you have sex so those interactions right now make no sense.
And seriously we need blowjob and deepthroat, with xray too, imagine SDT like gameplay in this with all the interactions, oh man
I'd probably add dick size slider, add some bulging, after all she is a robot, no need to worry about organs here.
The sex positions might also be made more interactive, let us adjust the limb positions more, penetrate from different angles and have that reflected in the xray view and stomach bulging wise, and of course lets not forget some cum inflation mechanics and maybe simulate artificial period and danegrous days where if you cum inside her she gets angry at you, no real period or pregnancy of course, that would be stupid and make no sense, what would she give birth to after all? An iPhone?
But if we're talking about smaller things I'd add different pussy modules that change it's depth, shape, how hard it is to penetrate the cervix (I know it's not realistic, I'm a hentai degenerate, don't question my kinks) and how quick it makes you cum, also personality modules that change her personality (who would have thought).
And if dev wants to add stuff like cuddling I'd add few more things, like maybe tickling, slapping, pinching, maybe also add some presents you can give her or have her relactions with the hero improve if you get her higher quality modules and limbs, add some minigames where you actually play with her and if she looses maybe she does some unique sex interaction or you unlock some sexy poses?