Not Yuri specifically no, manga in general. I was complaining about HameFura continuing post graduation a while ago for instance. I am however a massive GL reader and collector so I do know that most GL do not have this issue, most tend to be shorter than this even, but I'd argue that's fine. I like when a story sets up a premise, does it then ends.
I think you're valid for enjoying the series on just the character dynamic and wanting to see more happen to them. I also don't think not being a ronin ruins the series but that was the setup for the series, and that's kind of what bugs me. The series was sold to me as "a scummy gap student", she was a piece of shit, self interested, manipulative, and it was a story about her working towards a goal while improving herself. I kind of think that happened. We don't have a saint now but we do have a developed MC and I think the story may have been better ended there, but who knows. Maybe it'll surprise me with something down the line.