If you read my last post on this page, you will see that I said I believe the elbow drop is a result of accelerating too violently from backstroke to forward movement, using my shoulder muscles instead of just the elbow flexors, and overgripping the cue. In essence, I agree with what you are saying. It is just difficult to get yourself to avoid using those other muscle groups when a more powerful stroke is needed.
No matter how hard you need to hit, your backward stroke must be very very very slow all the time, even with break shot; you seem to want to force your shot in to gain speed, and that is when muscles react, elbow drop, butt hand twist inward..etc; most likely that happens as a result of improper or shorter backward swing length compared to the desired shot speed expected; synchronizing backward swing length with forward swing for a given speed is essential for lightly griped cue butt; not as essential with tight grip (Allison Fisher style). Getting the two in sync all the time, is pro quality play and takes years of practice, and complete knowledge of all 4000 shots possibilities.