Quoted from PinballSTAR:Why risk it - leave it as is as the company's issue to you, not one you maybe created or made worse by tinkering around.
I guess the dilemma I would have is this: let's say you have the rippling/pooling and you follow this advice and leave it. What happens if the rippling then starts to chip and JJP/Stern later tells you: "sorry, this is normal wear, here's some new posts or stickers (or whatever)"? Now you have a chipped playfield when you could have flattened it out and maybe prevented the chipping.