I’ve completed the course and seen it a few times because there is so much great material and tried to put it into use. I have to say that left arm coming down in front of my body instead of out to my left side makes a big difference with balance and accuracy and keeping them balls in the box and not going long as it helps bring your racquet tip pointing down. 
Your course is really, really great and I like how you get into detail on how to hold a proper hammer grip. Many instructors say hold the racquet as you would a hammer but there are many ways to hold a hammer. The proper way is having the heel of the palm on top of the bezel which you describe but many, many players don’t either know or describe properly. Really enjoyed your program and keep up the great work!