The heat shields on the catalytic converters on the DPI exhaust on my wife's car started rattling due to failed welds a year or so ago. Josh has stated a few times that these systems have a lifetime warranty on them, and told me directly that he'd repair or replace the cats if I sent them to him.

Well, somehow one of the cats become stuck on the muffler. Even prying the outer slip tube didn't break it free, so I sent the muffler and cats to Josh. He said there wasn't really any way to save the muffler due to the damage that would be/had been done to it while trying to separate it from the catalytic converter. I had to buy a new (updated) muffler, but he sold it to me at his cost, and sent me new cats, new (longer/updated) exhaust tips, and new installation hardware. It all bolted up just fine to the headers that were still on the car.

So, there is a warranty on these things if they fail, and the replacement will likely be an updated design (to me, that's a good thing).

I can verify that the new muffler doesn't have a heat shield on it. It also mounts slightly differently (only uses the lower mounts, which is easier to install) and seems to be slightly smaller. So, it seems that the issue the OP has will be fixed with a warranty replacement, which shouldn't be difficult to obtain.