Why not 4 calipers up front?

The factory stuff is good for multiple stops from 60 mph no problem, and from 110 at least once every 10 minutes, lol, in a 3500 pound 68 Barracuda, and can lock up 235/60-14s at 30 mph, so
what's your application? That 87D?
I have an 84D100 that stops just fine empty,lol. I don't haul much with it. The occasional motorcycle or quad.
But as to dual calipers;
First there's the traction issue. Just cuz you can loc up the rotors any old time doesn't mean much if the tires are locked up.
And then Secondly,there's the heat issue. If you put enough rubber under there to prevent loc-up, then you have to get rid if all the heat those pads are gonna make.
And Finally there's the strength issue.I think too much brakes will just rip off the wheels;that force has got to go somewhere, and before it gets there, it has to go through the BJ-pins, the UCA-bushings, and the strutrods.