I am surprised that made it through production. Certainly the staff in the factory would have noticed that when first assembling the playfield. To expect the end user would be content with that after spending 1000s is horrible... even for Stern. I hope they still get around to swapping that out for you.
My ST Pro playfield started to chip by the ball trough after 130 plays and 2 months. Small fill with superglue and mylar so far so good. If it spreads more or appears in other locations my distributor said he would try to escalate things.