Not that I have looked at the numbers myself, but I would think physicists would make those calculations using General Relativity, in which the effect you menti

Not that I have looked at the numbers myself, but I would think physicists would make those calculations using General Relativity, in which the effect you mention is already considered, not Newtonian Mechanics. It's a bit like this: https://xkcd.com/1758/ https://xkcd.com/1758/