[KTL]

The pad overhang can be fixed by using the Carrera rear caliper. Yeah, I know it's not a fancy Brembo aluminum caliper (much lighter than the iron Ate caliper, despite being much larger than the Ate) but the fitment and piston sizing is VERY good for track use. Rotors are cheaper too. Plus the non-drilled rotors have a bit better life span in track use

Turning down the diameter is not uncommon. It's done on front 993TT rotors for some custom installations. But I would not recommend using the 930 rotor in a reduced thickness. It starts at 28mm and min. thk. for replacement is 26mm. 24mm is WELL below that. Not to mention a perforated rotor is going to be more crack prone, and even more so when you remove all that thermal mass to make it 24mm. I would venture to guess that a 930 rotor doesn't have much wall thickness left after being cut to 24mm. This is because the air gap between inside of the rotor faces is fairly large.