I think it would be really good if Magnaflow would work out another option for x-pipe and cans as a set. Section 1 probably isn't going to change for the majority of people, and there are already good header options. Problem is going to be the very niche market of Z4M owners and low volume. I could see them coming up with cans pretty easily using a muffler they already manufacture. X-pipe would require more R&D and machine set up. That said, with modern CNC mandrel benders, once it's programed, it's pretty much a done deal.
OP - if you do get to help them out with some R&D, push for an x-pipe option