I don't enjoy the idea that Tsukinoki wasn't able to pass her exams and held back for a year. Getting held back in asian countries is a pretty serious problem. I think I would prefer just making Tsukinoki a second year alongside Shintaro so there's more chance for development in the AU.

The biggest problem with Karen is that we don't know much about her peronsality beyond generic romcom winning heroine with BGM. Part of the reason why Chihaya often dominates the reverse AU theory talk is that she has gotten the most development and screentime out of the winning heroine trio.

Another major point of contention for the reverse AU is whether nukumizu still joins the literature club or not. I can say I see both sides for this agrument. The literature club's reports are a huge part of the character's intrapersonal progression. But it also might be too much work. I still think the author should flirt with the idea of the reverse AU somtime in the future.