Just a fYI, brake rotors do not "warp"(unless the hub has issues), warping indicates that the metal surface heats and then deflects which is NOT what happens to brake rotors. Under heavy braking, particles of overheated pad material are removed and placed upon the rotor surface which then glazes over, then as the brakes are applied the pads glide over the stuck on glazed over pad material and digs into the steel on the opposing rotor face. This causes the rotors to WEAR unevely, not to actually warp.
I'm not saying that the above doesn't happen - in fact I know it does, and I have the rotors as evidence - however - I have seen brake rotors warp, as evidenced by the run out
at the edge - and since the pad does not cover the edge of the disk on this particular vehicle, there's no way that the transfer of pad material had anything to do with it.
I've had rotors warp directly after having them cut (turned), and I don't think it was a bad job, the pulsing of the pedal increased gradually as the rotor warped more & more - my theory is that cutting the rotor released "stress" that had built up over hundreds of heat cycles, and as the newly turned rotor continued to experience heat cycles it warped.
Vuzuki - if you think you can do it, and have access to the material - go right ahead - I could not find anything thin enough and springy enough. I did have stainless steel sheet, but too thick.