Don’t expect a step change in brake performance if you change to these bigger calipers and discs. The main reason Mazda have made that change is to get a bigger surface area and improve pad life. To get more power you need to go up in diameter and that is restricted by the wheel. You’d have to look at the mean radius to know if there’s an increase in power (torque). The only place they can go is length and that presents a different problem because a single piston on a long pad tends to bend it from the middle so they move to twin pistons to even the pressure. You can guarantee there won’t be much difference in piston area or they’d need to mess with the master cylinder and the brake booster. It’s a long way of saying that if you trot off to the spares counter and spend a woeful amount of money on the bigger calipers, discs and pads you might be disappointed unless it’s long life pads you are after. Mazda have anticipated that brake temperature might lead to rapid wear.
That was my thinking as I went with stock size slotted rotors made of better iron and improved pads on my Turbo as it already has dual calipers up front on a 320mm rotor (12.6").
I am very pleased with the performance of it, but every time I come down on the brakes hard, I see $$$$ float out of the window as those slots cut into the pads. LOL