bigger rear disc in rear than front a problem I assume?
I agree that the lever arm of a larger rotor does have an impact but if a tiny caliper is pinching a huge rotor, I don’t see the rotor size slowing the wheel any faster. A tweeker with a 3 foot breaker bar won’t crack a nut loose quicker than I could with a standard ratchet.
There is a principal known as “the point of diminishing returns”.
I'll respond to this because I believe the author has me "ignored" and the rest of you can avoid the drama.
I disagree It's not a case of diminishing returns. Because if a wheel locks in hard brake application, there are effectively no returns. The driver is along for the ride.
Tuning your brakes for best balance is a worthy goal, unfortunately that goal does change dynamically for many reasons that a driver has to account for, but getting the brakes balanced by whatever means, tire size, tire compound, air pressure, brake compound, proportioning, rotor diameter pad area, piston area. F/R Weight, aero effects, chassis dive, etc is a very worthy goal. A simple panic stop test in representative conditions will quickly and easily indicate the success of brake balance for that condition tested.
The goal of a street vehicle normally is for fronts to lock up first in dry conditions with no ABS in a straight line.
It also should be possible to lock up all four tires simultaneously , or some braking/traction capacity is being left on the table, ie you have more tire than brakes.
My favorite line on the topic, "brakes stop the wheels, tires stop the car"
