I got the same email, and reluctantly ordered. The price for the regular bare bones version is insane, especially for the quality of this fig. I may have a go at customizing him.
I guess the first thing would be to remove it and see if the zippers actually work. If they do, then I suppose you could cut the back, and maybe find a piece of fabric very close to the inner lining to extend it? Without a SM2 sculpt though, there really is little point in messing with any of that.