Is your inspection coming up?
I was considering on doing this except the way I was thinking was adding flanges on the pipe after he cut it up then add flanges to the pipes he just cut off, get 2 cats weld on some piping and flanges to those and this way you can swap the cats off the pipe with straight pipes a lot easier then having to remove the entire mid pipe every time inspection rolls around, just an idea I was tossing around.