Valid points and I yield their accuracy...

But in the absence of Old Kingdom Cubit Rods and the presence of descendants thereof I still say certain assumptions might be safely considered, to wit;

1) The rods were based on "something actual" that yielded the dimension changes...
2) This <whatever> was probably real, perhaps an actual Pharaoh's digit? Or the Chief Builders?
3) Because of that fact any mathematical solution must start with a certainty of the actual Cubit Rod length used on that specific construct. One cannot, for example, state "440 cubits * PI" when one doesn't have proof where specific cubit was in the 5% spread WE KNOW OF.

You seem to be stating that all cubits were definitely equal over the duration of the OK constructs. Can you link to the supporting documentation of this?

Because, it seems to me, in the absence of ANY recovered OK cubit rods, it is a bigger assumption on your part they stayed fixed than on mine they wandered just like the NK examples.

Jammer