From the CC FAQ:
1. I bought the Monster Max system and it's way too fast! How do I "tone it down"?
Answer 1: Lowest timing advance, smallest pinion and largest spur gear, and experiment with punch control. Always do these three things FIRST. It's not a good thing to dial down the top throttle endpoint, especially when you can re-gear, or just go down in cell count. The batts, the ESC and the motor will all run hotter than normal in a system with turned down endpoints to slow it down. The ESC is thermally protected, but the batts and motor are NOT.
Answer 2: We're working on RPM limiting, and some other software to soften the extreme nature of the system until the users get used to controlling this much power.
Answer 3: If you owned a Ferrari, would you have to drive it full throttle through your neighborhood? The system is not uncontrollable; your finger just needs time to learn how to control the throttle trigger on a high power setup.
Answer 4: We also have more great tips for slowing the systems down, and generally tuning them to your preference in our Monster Max tuning guide.
Answer 5: Drop down to a lower voltage, or install a lower kv motor.
So, they are suggesting you don't use the EPA to tone it down. Is there any chance it would affect the warranty if you did?