Jammer wrote: Might I inquire which you are using for your calculations?
The 20.8? 20.5? 20.2? 20.6? 20.1? 20.45? 20.62? 20.63?

None of the above, all of these samples of cubit rods are New Kingdom samples not those of the Old Kingdom.

In “The Pyramids Of Egypt” by Livio C. Stecchini he states: “There is a famous text of Egyptian geography which is found inscribed on three different measuring rods and of which other copies seem to exist. Even though the rods are of later periods the text of the inscription is considered to have been drafted in the Old Kingdom because of its linguistic style. The text says that from Behdet to the Apex of the Delta there are 86 schoinoi. Egyptologists have not been able to make sense out of this text, because they have declared a priori that a calculation in terms of differences of latitude was impossible. Hence, they have dismissed these documents as gibberish without even trying to test their figures in terms of latitude.”

”. Lepsius stated: “Yet it cannot be doubted that the ancients were able to make accurate measurements and possessed precise yardsticks, which could not be changed arbitrarily; it is curious that not a single one of these has yet been discovered. The question now is whether the subdivisions in the preserved specimens allow us to reconstitute this exact standard.” and this assessment has not been seriously altered in the past 150 years.”

In view of the findings of Lepsius and Stecchini and what has been stated regarding the cubit rods, would this raise questions regarding our understanding of the earlier Old Kingdom measures that we may mistakenly take for fact? Or we just to ignore this as all others before us have done?

Jammer wrote: They've recovered actual samples of all those measurements. Some qualified researchers believe this is because the official (finger) "digit" varied from 0.712 to 0.788 at any give time.

Irrelevant, all of the above are New Kingdom samples! Of course there are variations, the quality of the cubit rods reflects the quality of New Kingdom constructions.

Who in your opinion is a qualified cubit researcher?