Maybe I'm mistaken but I thought it was determined that the earth is not a "perfectly" round sphere.....
It's more sphere than not obviously, but near the poles there is more of a bulb / blunt effect that's stunting the "points" on either axes.
As far as your calculations, I can't call it. I haven't done that deep of a dive into it. But I felt the need to clarify that part before others continue.
Yeah, we addressed that a few posts up! Thanks for your input!!