Could do without the yandere shtick. Hope that gets dropped and stops being a thing, but I get the feeling it won't.
It's completely out of nowhere, and entirely against everything we have seen about Roxanne's personality. She encouraged every single step of purchasing Sherry knowing full well where it would lead, and immediately went into possessive, passive-aggressive yandere mode as soon as she was purchased. It's not even the same character anymore, it's like she suddenly gets replaced by Every Boring Generic Yandere Ever. It makes no sense, completely interrupts the atmosphere of the story, and ruins character interactions.
I'd rather Roxanne just be Old Yeller'd at this point before every chapter becomes, "Haha, look, Roxanne is jealous, insecure, and violent. Woooah, better be careful even looking in the direction of another woman while Roxanne is around! Better keep showering her in compliments, and platitudes, and lying, and tiptoeing around every conversation to keep her from going all yandere on you! Isn't that so funny?" No. It isn't. It never is. It's just annoying. It prevents the MC from freely interacting with other characters and getting to enjoy moments with them without Roxanne interrupting or being this looming shadow over it. Making interactions between other characters about her. It's entirely out of place in this story.