Hey @Matthew Trueblood -- great analysis as always. I was thinking about the same thing recently. He has been hitting some ropes lately.
One thing that was obvious to me was his stance in regards to his back knee. You touch on it when you mention after the third picture: "His weight starts more even, and he's less coiled into his back hip—not in a way that costs him the power hitters get from their back side, but in a way that loosens his front hip and leg to move more fluidly. "
Your first picture:
Second Picture:
Third picture:
One thing that hitters can do to generate more power, or even get more lift on the ball, is to have more of a squat in their stance. It appears in the first picture, he is not set up in a balanced setup -- so much weight is on his back leg that it had to be tough getting to toe touch consistently (not to mention the egregious stepping in the bucket that you point out 😉).
The second picture is a little better balanced.
The third is very balanced. He is also squatting a little more allowing the thighs to help with the power. I was going to say he keeps the bottom half a little more quiet, but he has a leg kick...
It seems like he takes his hands way behind his head on toe touch. That means the hands have to do more work to get the knob of the bat to the ball. That's just me, though. When someone is struggling, they got to get back to some more basics.