I don’t mean to be critical or disrespectful but I just did a google and found the A drill, it is the same stuff I saw in the 90’s at a course hosted by Lauren Seagrade. The first thing I picked up was heel up, toe up, in Charlies mechanics of running he states that the toe is dorsiflexed before ground contact. Over the years I have found that if dorsiflexion is constant then shin soreness is severe where dorsiflexion before contact avoids pain.