If you're talking about using full power .357s in a revolver, I have done it many years ago and it wasn't a problem. I am referring, however, to the compensated pistol in the pics where the "fireworks" don't all come out forward of the muzzle of the gun. With a pectoral index, I can imagine a bit of those "fireworks" flying into the face, which wouldn't be a good thing.
However, I have never done it with a comped/ported pistol, (and you may have been referring to exactly that,showing my limited reading comprehension) and could easily be wrong.