me.
i've been one-finger-braking since i first started using disc brakes.
you really don't need hope 4-pots (the 4 pot thing is a gimmick anyway, it makes sense on motorbikes where separating one piston into 2 means a smaller section disc can be used = lighter. it makes sense on cars where separating one piston into 2 means you can effectively fit a bigger piston between the wheel and the hub. 4 pot brakes are not more powerfull, but they are more expensive, so we get persuaded to buy them)
if you need to use 2 fingers, then it's a clear sign that you need to clean your discs, and buy some new pads – metal, they last longer.
no, i don't have forearms like popeye, i just have clean brakes.