I don't know about the KW, but my I had a pair of those springs given to me with my ProStar and they didn't do squat. You have to hook them under the elbow at the base of the arm, on my truck it was almost impossible to accomplish.
I had a similar issue with a big gap on my windshield not being wiped. I just switched to a set of Trico Tech blades, single point contact, and they seem to have fixed the problem, but only time and miles will tell.