Word D, is that what you called your "patented side-on undercutting"? I did that one by Trundercutting, but probably just frog started it on to my outer edge a bit. If you can imagine the mantel problem at the roaches, but with the undercut 10 inches higher, then maybe it'd be ace for that. With a break that wide though, I'm thinking knee bar potential or even, lie down rest. There we have it, it's even a great technique for horizontal cracks (i.e. breaks, albeit leaving them).