Smoothing off the edges with a dowel wrapped in 400 grit wet/dry is easy as pie on a stainless pistol, but another matter on a blued model.
A sneaky person would wait until the blue wore off around the edges of the beavertail, then carefully attack the sharp edges with wet/dry, then prehaps a dab of cold blue just to mute the shine. Properly done the results would be nearly invisable.
I have not yet closely examined the new blue PPK's. The ones I have handled feature a very dull, black finish. It doesn't look like conventional blue to me .... it may be the same finish as the M&P autos. Until I was sure it was conventional bluing I would not touch it, as it may not be easily "touched up".