Bob, thank you for the detailed explanation. Anecdotally, as a runner, I had always believed "you can never make up completely the time advantage you lose on uphills with the time advantage you gain on downhills" - at least, in a (theoretical) situation where the elevation changes are equal. Your recounting of the downhill advantage analysis would seem to put the lie to this belief. Maybe it is different for elite runners than for recreational runners like me. I ran all my lifetime PRs on flat courses. I always felt the % slowing going uphill exceeded the % accelerating going downhill in my races.
I agree with Pete that "the pursuit of perfection is the enemy of good enough", meaning that it seems there is enough "wobble" in the criteria data to obviate establishing exact elevation standards. We are considering athletic performances by human beings, after all, not Newtonian phenomena of nature, right? The unquantifiable - beyond broad measures - nature of these things even makes me question the need for one-sided tolerances.