I private messaged that guy with the channel and told him basically the same thing , asked about his machines power, told him about v groves and multiple passes.
Although unintentional what you wrote will be great back-up.
I really like the gold lenses as well, i wish my miller auto had one, i never really though about the light reflecting back but it is a very good possibility, i just assumed that because of the gold coating it blocked a different spectrum of light, like "blue blockers" sunglasses. Thats what i have in my over-sized lens Jackson, for when I get PO'ed at my miller.
As far as the cancer thing, there are occupation hazards associated to manufacturing practices from the past. One thing I know welders have trouble with is upper back and neck problems from flipping their hood 4 million times a year. It's one of those things the best prevention is absences, but then we would all have to find a new hobby,like speed walking. Ha
one other thing i have always heard is that welding aluminum is detrimental to your health, especially when you clean it with MEK.