In a follow up, I made two more shallow running 2.5 baits, with longer bills.
The first one's bill was a tad under 1" (the thickness of a pencil line) out from the front of the lure. It hunts at a low or moderate retrieve, moving back and forth from a straight line retrieve about 6", from what I could see in the dirty water. On a high speed retrieve, the bait rolls.
The second one's bill was 15/16" out from the front of the lure. It hunts at both low and high speed retrieves The water is too dirty to see how much.
Both baits has as identical as I could make them bodies, bills, ballast, and lip angles.
Clearly, the length of the bill is what affects the bait's hunting action, at least in my prototypes. My hat's off to Vodkaman Dave! He solved it in a reproducible way, so I have a great starting point for any cranks I make that I want to hunt.
So I know have four baits that hunt, two shallow (3-4'), and two deeper (6-8').
I'm going to paint the shallow ones with a red craw pattern, and the two deeper ones with a bluegill pattern.
The other two deeper baits that don't hunt, but swim just fine, I'll probably paint in a chart. sexy shad pattern, since that simulates lots of the baitfish here on the CA Delta.