Hey Cory,
Here is my method which came from Sergei deJonge; I add at least one layer of lamination materiel on the inside of the rim behind the location of the soundport. Must be done prior to gluing on the top and/or back because it will require a caul and clamps. It’s always worked for me. You can get creative with the layering of colors as well to make it look like purflings. If you are already laminating your sides, less will be required. I started out with Titebond but has since gone to epoxy. Never had a problem. Hope that helps; others might have a better method.
Paul