Agreed, the decent into arguing about the realism behind a specific character's personality (especially when it comes to sex) is redundant. The point of a story isn't the realism, but how effective the author is at conveying the story THEY want to tell.
That being said, the character that feels the most nuanced is Mallory. She's technically an LI but it's heavily hinted that she's either a clone of Sarah or somehow managed to break the RNG of the universe during conception (which is a whole different genetics topic). Jaye is the first LI we come across and both her and the MC had years of getting to know each other more in depth. Our first meeting with Mallory starts off rocky as the MC naturally distrusts her because of her background. However she also shows incredible depth and we see early on just how much in common her and the MC have. She's at a severe disadvantage as an LI compared to Jaye, and yet she poses a legitimate challenge to Jaye.
The elephant in the room though has severe implications for a potential love route with Mallory. Would it be classified as incest if she's a genetic clone? The argument could go either way depending on the lens you're looking through. The other challenge that a romance with her poses is what happens if the MC backs out later on? We see how the MC slowly helps her deal with her past as evident by her no longer hearing her father's voice constantly degrading her like we did on her trip to Aspen. An MC that leads her on only to break her heart could have severe implications.
As much as I adore Jaye I truly believe that the most well written character out of the whole story is Mallory (which is contradictory to my initial review of the game after the Ch. 4 release). Her tragic background makes her a sympathetic character, and her empathy makes her an easily likable character. I know Stoya won't share any spoilers here, but I wonder what he has planned for Mallory fans that want to romance her.