EQF,

How sensitive is Shan's shadow? Can it detect a mm shift over a several m baseline?

Do you really think a "rotation or shift in the crust" this large has escaped everyone's attention so far?

Some numbers: 1 mm/ 2 m is 1 part in 2000, or 0.05%.
If the crust twists this much with respect to the Sun, that means a rotation of roughly 1/2000th of the Earth's radius, or 3 km.

Don't you think we would notice such a movement on GPS? GPS has accuracy of less than a cm on daily measurements. Or are the GPS satellites supposed to be twisting too?

John