While its really the asymetrical requirement thats the most intresting, meaning possibly some form of nonlinear effect, Im wondering, because its not really mentioned in simple explanations, do people who do the calculations, add in the mass equivalent gravitational field, of the energy contained in a gravitational field, to that graviational field. I thought that useing simple approximation suggests the mass equivalent of the Suns graviational field, is roughly equivalent to the Rest mass of the planet Earth?

The difference in velocity measured is fractions of parts per million, or an accuracy in the speed of light of tens of metres a second or better?

Will they be using the external measurement possibility of GPS to improve their measurements, accuracy, or is that one of the options already put forward?

Hope this has a nice measureable effect that follows predicted values. Especially if the prediction is based on methods which present thinking is uncertain with. We need new functions, its been over 50 years of stalling in solving the relationship between gravity and quantum mechanics, and others, and I hope this helps some.