Bluetickhound - I am sure by now, after reading all the comments on this marvelous thread, you have realized that there is more than one solution to the hunting problem:
I like Mark's shifting ballast solution. I think I understand how it works.
There are others that use transitions between stability and instability, by moving ballast around to flirt with blow out. The Lure Professor, Bob said it well, that the problem is if you go too far, the lure is useless, which means that you make a lot of firewood. If you wish to explore these methods of hunting then yes, you will definitely need to play with the ballast. Like BobP, I had success with this method but was frustrated by the lack of consistency from a production stand point.
I spent a couple of years working on a special lip design. I got it to work for a while and then lost it after a few months away. The lip was not pretty and not really an aesthetically acceptable solution so I had to be realistic and give it up.
More time away and more theorizing and I came up with my current idea. Ballast has no effect on this solution, also the lure never blows out if you get it wrong.
This makes four quite different methods to achieve the same result and I have no doubt that there are more.
Dave