Mac,
I agree with Chris that the essence of the Blake swing is "dragging" the upper body down by dint of leg action. Some of us vary in our perception of the strength of this leg action. Richard Wax feels it as a simple "turn," whereas my feeling is that it needs to be a "thrust" of the legs to generate sufficient power for the swing. Curtailing hip turn and reducing the amount the lead arm goes round the body (inside) are essential elements to setting up the body for dragging. With respect to trail elbow, if it doesn't go too far back in the backswing and is "connected" to the torso, it will be dragged down into its correct forward position.

Over the years I have found some golf analysts who don't believe that trail elbow could be as far forward at impact as depicted in Blake's books. Some say it wouldn't be desirable even if possible. Blake sent me only one set of photos years ago showing an action (vice posed) picture of him near impact (photo 3 in last Mindy set in the album). Trail elbow is not as far forward as shown in the book drawings and Blake annotated the photo to indicate variance with ideal trail elbow position. Jim