I had a similiar idea. I want a full system but I hate the looks of the Area P muffler. Just from general reading it looks like the slip-on mid pipe and muffler is 2" and the full system is 2.25". My Leo Vince slip-on is 54mm which is 2 1/8. I've been wondering if a muffler shop could swage the pipe out big enough to fit over the Area P but who knows if they would line up or not.As a retired guy that once did exhaust work for a living, I can tell You that most stainless exhaust tubing cannot be swaged to a larger diameter. It will split. The exhaust tubing used for aftermarket bike exhaust however, looks to be much higher quality that automotive type, so it could be possible. It will ruin the pipe if it splits though, and doesn't give any warning. It just goes,"boing" & that's that.
Just thinking out loud.