It pretty much becomes a texas (or frog if you have a additional frog style chest ascender on too) if the chest roller were to fail. You can use the same system with a store bought chest roller too if you something more bomb proof then my home made roller.
I've actually been using Cinton's hybrid system for awhile now and I really couldn't be more impressed with it; It's handled every pit I've thrown at it with ease. The best thing about his system is the compact roller in my opinion. Another nice feature is the ability to go from a ropewalker to a texas almost instantly for those miserable lips. In a worse case scenario with the chest roller, in my experience in using his system you would not heel hang but just end up on a texas with the bungie still on the knew ascender. At that point you just take the bungie off and climb texas.
Clinton, do you think you could post a video of yourself using this system sometime? I'm pretty sure I have a good grasp what you're talking about, but I think it'd help to see it in action.
I have been using a system very similar to Clinton's for years. It's a Texas system using two handled ascenders with a foot loop attached to the lower. Then I can add a tiny chest roller (similar to Clinton's but better;-)), a foot cam, and a knee cam held up by a bungee that runs over my shoulder to make a very efficient ropewalker. I have used this for nearly everything you can think of. It works great.
Haas is super light, small efficient, ergonomically correct and can be bought ready to go. its takes about the same amount of time to open the packages as if does to set up it can be bought at tree stuff, https://www.treestuff.com/store/catalog.asp?item=3535 and its as fast as a frog or rope walker,