Timely, I was talking to Dave Crockford about some DDRC diving he did back in the old and bold days...
They ran the profile a few times in a pot then went out and did it for real........

90M, 30 minutes bottom time, 90 mins back to surface, 4% N2 Heliox and PPO2's of 3.0 on deco using CCR+FFM... It worked.