I kinda echo Stan here.. Im not one who doubts people's abilities who have conditions, but this scenario may not be the best decision for him. Just out of curiosity here... & this may show lack of knowledge on diabetes, but what about blood circulation, are there larger risks for him pertaining to suspension trauma? I know I've had my legs go numb a few times in couple long awkward free hangs. I'd be curious if that has more serious consequences for him, whether it be immediate or even long term down the road.
The whole suspension trauma thing kinda weirds me out.. i never really thought much about it, until I saw a mountain climbing video on it, I think it was black diamond. IIRC, they did an experiment with an EKG machine, wired them up & suspended these rock climbers who volunteered. It's was as if one minute these athletes were fine, just sitting in their harness; the next minute EKG showed they were about to black out & exhibit cardiac problems. IDK..maybe I interpreted it wrong, whatever it showed, it was an eye opener.