I like that the game holds to certain limits. OP says that the game is focused on the mind control fetish, and they're 100% right. The scene where you change Nozomi's name and she totally thinks Kyou's BSing her... that IS erotic for some, and adding some strait up porn-esque bits might cheapen that part of the game. Or maybe not: the robot ending doesn't cheapen the rest of the game, so maybe I'm wrong about the whole "cheapens the experience" idea.
That said, I do think the game could be a bit flirtier/pervier without going too far: while Hiroko's branch is a fun and entertaining read, she never gets MCed in a pervy way like the other two; she's a cat for a cg (which is someone else's fetish I'm sure, but didn't do anything for me), and then stuck to the ground (which is funny but not sexy imo), but even when Kyou makes her ok with what he's doing, in his mind he's helping her. He doesn't really try anything (mostly because he's scared Hiroko won't let him, but still). He gets a LITTLE more risky with Sayori, making her alternate persona have a crush on him, but even then that romance is pretty chaste all things considered, and nothing pervy happens after that because everything centers around "oh wow she's really still under trance? That might be a problem".
The update in Nozo-Reversal (I think that's where it is?) with Nozo thinking her clothes are Kyou's and then almost leaving the house in her underwear is along the lines of what I'd like to see more of: it's not raunchy or sex-centered. It's just a dollop of pervy mixed into the mind control. I'd like to see more moments like that with Hiroko and Sayori...and I wouldn't say no to some moments with Risa either ofc.
anyway, that's just my 2 cents. Overall I trust the dev to make the right choice, even if it's not what I personally think the right choice is.