Our machine will be capable of exceeding the envelope, but will be programmed to stay within it, using potentiometers. We should be well within the cylinder.
However, I do worry about being over scrutinized, just because of the physical possibility.
Also, last year we were tipped over twice during the season by a collision, while scoring tubes. Since we were fully extended when we were hit. We were called for a 72" violation, while lying there helpless on our backs. (ouch!)
I saw this happen to other teams as well. So if you get tipped you may be in violation of the cylinder rule.
And finally, I really hope that FIRST can make a definitive statement about how this rule will be enforced. Many teams are still in the early design stage and it will make a huge difference.