OK, here we go. I guess I'm on my 4th purge cover for the B2 primary. The current one I have, which was the first to be the "current style" where the cover uses two different kinds of material is totally FINE. So, AA have fixed this issue for sure. Here are four old ones. From 6'oclock, the original from my primary; 8'oclock #2 from primary, 12'oclock a spare for Octo that is at the "tacky" stage, and 3'oclock #3 for the primary. Second pic is a close-up of what's left of the original purge cover. You can just make out some text still on some of the larger bits.
These bags have been sealed in a Pelican box since coming off the reg, which was also kept in a sealed Pelican, so they have had very little UV. Although this started as a debate about "UV rot," I don't actually think UV is the issue. It's more like "aging polymer rot." But, as I said above, the new ones seem fine and anyone with a modern AA can just enjoy their dives and not worry about this at all.
These bags have been sealed in a Pelican box since coming off the reg, which was also kept in a sealed Pelican, so they have had very little UV. Although this started as a debate about "UV rot," I don't actually think UV is the issue. It's more like "aging polymer rot." But, as I said above, the new ones seem fine and anyone with a modern AA can just enjoy their dives and not worry about this at all.