I have heard the hole in the top center is to help move the safe around during manufacturing. They put an eye bolt in it and lift it with winch.

I have a Browning Pro Steel safe and drilled the holes myself without any problems. I drilled a pilot hole first, then the full size one. There was no chipping of the enamel. I did not use heat first. I figured if I messed up, it wouldn't matter because the holes were on the bottom and back.