An old idea of mine which I've never presented. I was thinking of a lock that would connect disc instantly when pedal is touched and unlock it when foot is raised so that disc spin freely without actually adding the weight to the wheel during acceleration, and have much less intertia before braking. It would improve both the braking effectiveness and acceleration.
When driver touches the pedal, the disc would actually begin the braking process due to its weight that needs to be accelerated, even before the pads engage, and slightly cool themselves just before the heating up under braking.
I reckon that it could also be used when driver needs to additionally cool discs on the straight, with just touching the peddal.
It would also enable the disc to maintain its speed during slowdowns without braking, thus maintain its cooling.
And possibly, if accordingly designed, the air pressure from the brake inlet could do the spinning of the disc and level up in a way, likely reducing the drag.
4 discs x approximately 1kg = 4kg less to accelerate, with ditched inertia under braking.