I think you are wrong. Evo owners powder coat their rocker covers and those are next to the exhaust pumping out 500 degree's and more.
not really the same...........
another view... off a nother forum
Exposing a forged aluminum alloy to 375 degrees for 30 minutes can have a negative effect on the strength of the alloy. It will "over-age" the alloy and begin the annealing process. DO NOT DO IT. You will no longer know how strong your wheels are.
Since forged wheels are usually weight optimized for the vehicle, reducing their strength is unwise.
Most wheel companies, and Porsche, will void the warranty on the wheels if you refinish them.
As for chroming, don't do that either. The chroming process causes embrittlement of the alloy, weakening it and making it susceptible to damage under high load.