I don't know if calling the most aggressive girl "best girl" is a good thing. It's good that she is getting past all the flack she had earlier, but at least for me, how she acts then and now are demonstrating to me a "I haven't reflected on what I had done" and an author's wish streak. Her saddened state before was exactly reflective, and was short-lived, while the statements this chapter feel like a lot of loopholes as to why she can press that her romance is fine (if anything, she's pressing all the cards in her favour). Just how much wayward is being given to her is not funny anymore. But I do need to consider, this may just be the character development that people sought, whereas for me, it's not as impressive. She was deeply hated, and maybe the author didn't think it'd be taken this far (although spiking a drink should not be so easily brushed off, unlike some individuals who only cares about the now) and wished to bring upon her an interesting turn post-acceptance... but I digress.
Ichika, as conscript117 has said, is rather passive... or maybe she is being active, but in return shies away from the next step after. My usual concern with characters like her is that they show up as "I'm the big sis," and while irl older sisters may feel burdened by the responsibilities, it's not appealing that she is moping about. Surely, it could be that she still upholds being the oldest somewhere, but here she's oddly holding back quite a bit. Maybe Miku sapped any semblance of Ichika's confidence.
I'll hold off on talking about the other three for now...