OK Kevin...per the response:
"These spec lines are from the original "Limited Prep" classifications that were made, many years ago, and that was the process/ruling at that time. As the "Prep Level 2" ruleset matured, and more waves of cars got classified to it, this measurement method was re-evaluated and changed to the current rule."
What confused me was these two sentences. There were no changes between the original limited prep rule and the current rule that I can find. So, IMHO, we have an "old school" rule that has passed its exploration date.
Note that you have had a couple of prominent engine builders opine here (along with an amateur) in favor of this change. If you canvass others I believe most, if not all, will be in favor of this change.