Depends how the porting is done. I HAVE been hit with debris from porting with a hard angle. It IS noisier.
But, if it helps you, then so be it. COmpensators, porting, and the like are usually reserved for higher pressure loadings, so their effectiveness on a 12ga shotgun is severely diminished.
Now, put an effective brake on a 7mmRM rifle and the difference is night and day, although it is EXTREMELY loud.