"Because the trailing edge of the pad is hotter then the leading edge, and this fact is what makes a 2 piston (or single piston floating) caliper cause the pads to taper. By adding another set of pistons, you can make the first set smaller then the second, thus offsetting the taper from the heat buildup."

Wouldn't you want the smaller piston to be at the trailing edge of the pad to decrease the pressure there and even out the wear?

P.S. Thanks for the write-up. Definitely some good info in there.