I don't have anything against a wide meplat and a heavy bullet. I am aware of how it works. It is a very tried and true design. I know its cheaper. They are not new to me. I am a big fan.
The lehigh bullets are not a gimmick, and they penetrate 3A plate armor at 1400fps when a wide meplat won't. When the same bullet is loaded in reverse, with the flat base acting as the face of the projectile, it does not penetrate the armor. It digs in, but does not go through. That is because it is a function of design in this case, not purely of velocity and weight, otherwise any shape tip would penetrate, especially the other face of the exact same bullet.
To answer your question about what function mine or the lehigh bullet would serve in .45 caliber or greater, at speeds near 2000fps, the answer is simply to be as destructive to tissue as possible with one shot. If you watch many videos in gel or otherwise you will see that these bullets cut surrounding tissue in a way no others are able to replicate, and that the results are based largely on impact velocity times the width of the flutes. The main deference between the extreme models are flute width, and meplat, which are contingent on each other. The wider the flutes, the wider the force is spread to cut tissue. This gives 18in of penetration around 1400fps and slows the bullet once it is inside fluid based tissue, and it releases its energy on the spot in a concentrated area as drag with the defender. The penetrator has narrower flutes and as such holds more energy for penetration and cuts a little bit less, while having a more blunt face for impact trauma. The PWC of the penetrator is still larger than comparable hollowpoints, but not as large as the defender, but more stable with less pronounced taper towards the exit.
The effect of the wider flutes create more drag than than the meplat. My idea of directing that effect at closer to a 90° angle in a narrower channel is to increase the drag considerably the moment the bullet enters tissue, while also maximizing the hammer effect possible with the faceted face. I want a spinning, bidirectional wound cavity at least 6" across at the point of entry.
A nice hard cast keith or LBT is like a hammer, whereas the lehigh is something more like a drill.
The hammer has an awesome destructive force upon impact, and then cuts along the edges on its way out the back of the target. The drill has less of the rippling, brute impact force of the hammer and it does not rely on mass. In fluid based targets, however, the drill shape utiziles forces to cut beyond its edges. The scope of that is variable to flute shape and path as well as velocity.