I'd contact him. He'll make it right for you. He doesn't like dissatified customers. He's a great AMC guy.
I did contact him. He said :
"First Ive heard of the puckering corners. The replacements have a relief
hole and cut out.
I tried one and I see what you mean.
It seems the holes were punched in a little too much.
If it becomes a problem,carefully remove the corner and use a hole puncer
and remove just a little more. Remember to open the flap first.
I have some pieces you could use for filler to extend the lower channels.
It should be ok without but if you want i can send some.".
I don't know if I would say I'm dissatisfied, a little disappointed yes, but I did manage to get it to work satisfactorily.