Most of the stories I remember (and my own from when I had a #2) are:
* cut it in half and put it on two shelves - Flat on top shelf with fat cap up. Point on lower shelf with fat cap down.
* lay it on the rack diagonally so it just barely touches corners as it'll soon shrink and be fine
* fold the flat under the rest of the brisket to reduce its length
All of these methods have been reported as practical and successful. I wouldn't personally do anything that would leave part of the brisket dangling. I'd be worried that it would just tear off and fall.