I'm afraid I've missed the significance of your work. I see that radii of the earth through the two locations subtend an arc of about 55.2° but I don't follow you from there. I'm assuming you, as you state, have confirmed the article's geometry. However...
The author also has the caveat "the figure most open to interpretation is the distance in pixels between the tips of the crescent."
This interpretation becomes even less reliable when one realizes there are no actual "tips" in the proposed monument at all.
And my point is there are a large number of other secondary points on the globe about which one could imbue with significance as well. If, for example, the interpolation of the points is off a tad, some could claim it points to Medina, Hebron, Qom, the Dome of the Rock...
But I greatly appreciate your work and effort and skill in doing this. Thank you.
I do what I can.
I suppose the next thing to do would be to harvest the biggest hi-rez plan view of the proposed design and double-check the author's derivation of angle, giving my own tolerance for angular accuracy.