On a construction and practical level, this is another fabulous pattern from Cashmerette. I've been sewing since I was a kid and am in my 60's now, yet I love learning new techniques from Jenny and Cashmerette. I made wearable muslins in both the Webster dress and top versions. The pattern does have a tremendous amount of design ease built in and that probably was a factor in the fit issues. I tried sizing down two sizes, but was still much bigger on me than was flattering. I ended up just doing a major alteration on the garments , taking in the shoulders, shoulder length and width of garments throughout.
I did, afterwards, see a blog article where Jenny described how to make the garment more streamlined. And now with the high bust measurment to help with size choice that would make a difference as well. But the bottom line for me is that perhaps this pattern just isn't for me. Many women, I'm sure, would love the flowy design ease in this garment. I love the back of the garment and will probably work with the pattern and hack it with another Cashmerette pattern, keeping that fabulous back of the Webster.
On a side note, I used to only buy the printed patterns, but am a convert to the PDF which allows me to reprint pieces as needed. As I learn which sizes and grading suits me best, it's lovely to just go back and reprint the new size. The taping together of the pattern pieces is well worth the effort to me.