I think Takahashi’s designs work best when he is working in original characters. He knows how to make them cute and expressive.
The problem here (in my opinion, of course) was that they saw that one of the many problems of Crystal were designs (whether they were difficult to draw, inexpressive, not liked by the fans) and they chose someone who had successful designs for a younger demographic (which didn’t work either)
So in the end his job was to simplify designs but he didn’t have a lot of creative freedom. I think the mixed reception was to be expected if the only thing you have to do is simplify, well ... we can see the results.
He ended up picking the works things from his designs like horrible skirts, teary eyes for example. And that’s strange because he can design complicated skirts and cool eyes but well.
Bringing back Tadano, was the best decision even animators praise the decision because she has been doing character designs for years, her eyes expression and proportions are really good, because in the end she is always think in how these are going to be animated. We will learn more about her thoughts and creative process in the art guide and I can’t wait for that!