Hey Carl. Also look at the fine print and see if they say anything about the maximum chlorine concentration that will void any warranty. Digging into the recesses of the brain now but had one years ago that I think stated 1.5 ppm max. Thought it was a slipped decimal point misprint until I checked and found the number was right. When was the last time any pool was at 1.5 ppm?
As for folding and not rolling, I don't get it. Seems to me rolling would put less stress on the material as there are no creases that would creat high stress points for the bubbles.
On covering the thing, any solar cover folded, rolled, bubbles, or extruded, will let the infra-red pass to the inner layers and heat the thing up. In strong sun I'd bet the inner layers could reach the melting point. I roll mine and use white bedsheets as a cover. Even then, when I unroll it the inner laters are much warmer than the outer layers.
For what it's worth.
Al