1." Is your model compatible with the idea of an exterior one wall ramp on G2 for the first few courses"
a. Yes. Thou once you reach the beginning of the Grand Gallery, I feel they may have used a Lever Crane inside the Grand Gallery, for the 40 ton stones. When I designed the Lever Crane, the cavities in the sides walls, matched what would be required to lock such a device. Additionally being used for rollers in tandem, with a space underneath, for returning empty skids. My first interest in the Pyramids gained in intensity, 40 years ago, when I realized there is a steep long cliff on the G1 side. If you had access to water, ramps could be built, to perform much of the stone lifting required. Water is very heavy, and can be employed to the heavy lifting. Unlike the Causeway, that drop would really offset heavy stones.
I have more illustrations, and will post time permitting.