True. But he is trying to find 1/16th neon material and therein lies the problem. Your idea although there's less laser time on the lens, hence less chance to warp it leaves a couple other problems.
It is still only going to be 1/32" deep which wouldn't be enough to be visible considering the fact that a laser cutting systems cut a hairline for one pass. In order to see it at all he would have to widen the thickness of the cut pattern to a minimum of 1/8 inch which increases immensly the amount of passes and reintroduces a heat and warp factor and will still be hardly visible because of the depth. Part of the neon effect not only comes from the material formulation but also the angle of viewing so the fact that when you see the effect with mine you are roughly viewing from an average of 45° angle. And also would leave an 1/8" wide groove with only a 1/32" left of material holding it there and that would make the lens effectively a knockout piece with one good bump on the face.
Another reason is I don't think he will be able to find neon material in 1/16th inch. I had a hard time even finding 1/16" Smoke. The only reason I did is down here in Fort Lauderdale is there are a few airplane remodelers here and they are one of the biggest purchasers of it. They use it for some kind of windows inside the Leer type jets.