This sounds like it would be your first time drilling powdercoated metal, so I would approach it with a decent amount of caution and planning.
You should be using sharp bits and a decent amount of technique to do it without fucking it up, to be blunt.
The main concern for you would be heat, I would think. Since the flange of the button extends over the edges, you could probably deal with a little scratching and chipping, but you will need to pay attention to overheating the metal/powdercoat as you drill it. Chipping will depend on how good the powdercoating was done.
Maybe pinchroma will chime in, he is the resident expert on powdercoating.