I haven't seen it on any of my 3 visits to the factory (for customer tours), but I've heard about the Amish worker who devised a quick way to make the 1.5" hole in the roof decking. Rather than use a hole saw (smooth sides and even, round hole) he worked out how to use a claw hammer, one quick blow to the 3.8" OSB and "voila" an instant hole. No matter that it's rough on the edges and splintered under the decking, it's covered up by the TPO roofing, and nobody will ever know......
I can't confirm that kind of workmanship, I never saw it on my tours, but it does sound like something that would happen in a Forest River plant, but certainly not in a Keystone plant... Hmmmmm