This my not be the optimum time to mention it, but....cast magnesium wheels are still close-to-state-of-the-art for performance cars But they flex while being driven, like all wheels do, And with cast magnesium, the resulting stresses never go away.... until they combine with mag's porosity to form a crack or an actual broken wheel. But we have found a way out.
We can anneal the wheels in your kitchen oven. Annealing temperature for cast mag is only 275-300F for about 3 hrs, followed by VERY slow cooling. This should be done every ten years or so. I got the idea from our Navy who fly fighter jets with magnesium wheels, After l00 hours of use, the military anneals their wheels during major overhauls, or throws them away if chipped.
When I worked for Lockheed Aerospace, I verified the info..This stress-relief should also be done if a lightly damaged Campy or Halibrand wheel is TIG-welded. The only drawback is, the 300F temperature will turn the protective chromate-based undercoat paint a tannish color, so you will need to repaint your good-as-new mag wheels. You need not strip them to repaint, though.
Powder coating is often done at 350-400 F and that will anneal Campys too if you cool them down slowly. There are a LOT of annealed Campys running around the US these days