Still just a few rounds in on learning this swing but made two big discoveries. The first one was I was not able to slide the hips far enough for the driver. I reread the book an noticed outward pressure on the knees. It added 3-4 inches of slide without effort. The second one was "arms straight". I kept concentrating on my left arm but had trouble getting it to straighten fully at impact. This resulting in some thins and fats. Then I started working on keeping the right arm connected on one of the drills and now the left is straight every time, with consistent low point after the ball. I am excited about the last part.