Well I can't speak to that, and given the past your perfectly justified in how you feel.
That said, I have had in the past year about 3 submissions of 25 moderns and this Last 2 submissions were 20 and 18 books. In that time the only I've had with rings are the 2 in this last submission , also there was a sin city cover that is mostly black, no rings (although if it were common would stand out if there were) but it had a piece of stringy plastic from the sonic weld that seals the case. It looks like a long squiggly hair but I can tell the difference
Still that said
If you look on this forum on the main page you'll see a sub forum called cgc announcements. In there you will see a thread called Newton rings that cgc started.
There have been less and less posts in 2 years time, unfortunately some members have been hit more than others. Silver lining on that, they're good about posting there. That said I'm not sure if others think to post there, but for example you can see the photos of my books there, those 2 that just came back.