Hi Don,
Now I could be wrong, but a matter of perspective can cause some to miss the obvious? By your figures with the arc second cubit of (20 34/55) 20.6181818...inches. Saqqara enclosure wall1 long side of 1800 feet x 12 = 21600 inches / (20 34/55) = 22000/21 cubits = (1047 13/21) cubits 1047.619048
Short side, 900 feet x 12 = 10800 inches / (20 34/55) = 11000/21 cubits = (523 17/21) cubits, 523.8095283 1800 feet x 3 (2 long 2 short sides)= 5400 feet.
5400 feet x 12 = 64800 inches.
64800 inches / (20 34/55) Royal cubit = 3142 6/7 cubits = perimeter Saqqara enclosure wall
3142 6/7 = 22000/7 22000/7 = 22/7 = 1000 perimeter wall, in cubits, at Saqqara equals 1000 times 22/7 cubits.

(20 34/55) = 20.6181818...inches x 10 = Kings Chamber width 206.1818181...inches
206.181818...x (8/(14/11)) = 1296 inches = perimeter north wall Kings Chamber.
Just my perspective.

Cheers,
Jacob