Don’t worry about the rear brakes they don’t do too much. I’ve got a DC2R and am reasonably aggressive on brakes (my lap times seem to be there or thereabouts with other DC2Rs). I’ve had brake temp paint on my brakes on track days - the front paint indicators were just starting to show 600 degrees and the rear indicators didn’t even get past 200 degrees. Get hard on the brakes on circuits (//Calder - turn 1 (5th to 2nd gear), //Phillip Island - Honda Corner (4th to 2nd gear), MG corner (4th to 2nd gear), //Sandown – turn 1 (4th to 3rd gear) and Dandenong Rd (4th/5th to 2nd gear) and Winton – cleavage (after the sweeper) (4th to 2nd gear) some of those corners require very heavy braking (200ish kmh to 70-80kmh in around 80-90 metres) and more rear braking is the last thing you are wanting more of

I’ve done a fair few track days with braided lines, AP 600 fluid and harder front pads and stock rear pads. The fronts (pads and rotors) have been replaced numerous times, the rears have been replaced at over 100,000km (I think it was the first time they’ve ever been done). When my shocks were on their way out I was starting to pitch quite heavily under braking (front down, tail up) and was even 3-wheeling at some points.

While I admire your forethought I think that spending lots of $$ on vastly improving the rear brakes would be better of spent on other areas.