I'm aware of what the straps are made of. They will not damage the aluminum, now will they scuff it. The wear you refer to is not a scuff, though it can mar the finish...possibly. I'm not saying I would use those chains, but the dire warning of scuffs is ridiculous. You can also use zip ties as "chains." I used to commute in the winter and rode on a lot of ice, I never used higher pressure to gain traction. A narrower tire will sink through snow to get to a place where they can gain traction, but running a higher pressure actually works against traction, reducing the contact patch. A wider tire will float on top of snow, which can work well too given good tread for the conditions.