My wife and I both currently run and have run dogs that have NO start line stay (all BCs); but they are pretty good about waiting to leave us in their dust until their leash is fully off and on the ground.
That said, there have been times with all 4 dogs when they bolted prematurely and got themselves, us or all parties concerned, tangled up . . . and we SHOULD HAVE BEEN FAULTED or 'E'd ; but we were not for whatever reason.
We trial VERY infrequently now due to our dogs' ages and the lack of reasonably close trials; but we work on impulse control DAILY in a variety of situations here at home and with agility equipment here at home . . . and our dogs behave quite well. However, that doesn't translate all that well when they are on an adrenaline rush at a trial.
Our biggest concern is NOT whether we get faulted or eliminated, our biggest concern is the PUBLIC'S perception of how our "trained" dogs are behaving. John & Joan Q. Public don't see the score sheets and don't understand the judge's signals, so there is a very real chance that they walk away with the impression that NADAC is tolerant of such behaviors, which is NOT true!!!
I do not believe that this is a new policy in any way; but I do believe that it is a policy that has, over time, lost it's "teeth" in eforcement. Fact of the matter is that I wish that this policy had been STRICTLY enforced back when we were all getting tangled up . . . a specific fault or 'E' at that time would have made us take notice . . . and we would have devoted as much or more time and training into start, as well as finish, line behaviors as we did with all of the obstacle and path stuff . . .
Al & Barb Ceranko, Dred, Gael & Pelli in OH . . . Flurry & Kali, probably still getting tangled up at The Bridge