I don't want to muddy things more - but the "cutoff" times at Barr and A-Frame are NOT, as I understand it, based on a runner's start time, but a raw clock time that starts at 7:30. Since the last wave (which I'm in) starts around 7:21-7:22, there's still almost an 8 minute buffer for those cutoffs. I'm a big fan of the staggered start. Being at the back of the pack, and more of a hiker than a runner, in prior years I spent a significant amount of time behind folks who started out fast and slowed down and even took breaks on the "w's".
Only the finish would be figured on a runners start time using chip time. Last year, a few runners made it to finish with a chip time over 6:30, got a medal, but did get a DQ once their chip time showed they didn't make the 6:30 cutoff.