Is this muffler temporary?
I don't know much at all about turbos, but I believe that the wastegate is what regulates the boost. Wouldn't putting a muffler (restricting airflow) on it effect the boost? I know you do your research, and you would know a million times better than me, but it's just a thought. The reason I ask if it's temporary, is if it is, then just baffle it, and the looks really don't matter.