I don't know about high temp paint, but I know if you use an over to cure powder coat you are absolutely never supposed to cook food in it again regardless of how you clean it.
The new fueling requirements to meet emissions run bikes very lean, which increases heat. As yonsson said a fuelx will help. In general I've always found twins to make a lot of heat. Ducatis are very bad.
None of this is really about braking power, it is about having more thermal overhead. Unless you are tracking your bike going to other calipers or larger rotors is simply not necessary - the brakes are sufficient to lock up the tire so there is more stopping force available than traction...
The issue seems to be that the stock rotors eventually warp/get hard spots due to metallurgy. Nothing other than different rotors fixes that. I've never had an issue with how hard the bike stops and adding the larger rotors and brembo pads only made the braking better.
I just happened to look as I was chucking up a piece of 20mm aluminum bar stock in the lathe to make my own. The bar stock would have cost almost as much as I paid for them from Amazon.
I did not and I didn't see your comment until it was too late to add to that order. $50 from italy for a pair vs $120 in the US. But I saved so much on the rotors I didn't care and just ordered them from amazon.
Holy hell!!
Edit: Just ordered the Brembo rotors. I like the look of the Galfer better but if it is metallurgy that is causing the warping issue I don't want to find out that the larger rotors will wind up with the same problem, I'm just now starting to feel pulsing right before I stop.
Rottweiler has a front wheel 320 kit for our bikes using Galfer wave rotors, going to try that. The best I can find the Brembo 320's are on on the order of $400 each...
https://shop.rottweilerperformance.com/oversized-320mm-front-rotor-kit-790-890-990-duke/