Though I'd share a bit I learned today. I contacted Dave Zeckhausen today regarding my brakes/pads, was given a little info about brake ducting and I also asked about possibly going to 2 piece rotors. Here was his response so thought I'd share.
Juice I know you mentioned rotor cracks and you have ducting so though this might interest you too....
My concern with adding brake ducting is it will lead to rapid, wide temperature swings and subsequent formation and spreading of microcracks. You'll start chewing through the 1-piece rotors because they'll crack much sooner.
Changing from 1-piece to floating rotors will NOT increase the thermal mass. Just the opposite. By replacing the heavy iron center section with lightweight billet aluminum, isolated thermally by float hardware, we're going to see higher peak temperatures. The same amount of thermal energy will all be in the rotor rings, thus higher temperatures.
One way to increase thermal mass is to switch from 355x32mm to 380x32mm front rotors. It's not a simple caliper bracket and rotor assembly change. It's an entirely different 6-piston front kit. That may run into wheel clearance issues, so I've attached a wheel fitment template that you can use to check, if you want.