Basically, the Sun is NOT very high up only about 100-200 miles.
So when the sun is 3000+ miles away, Fata Morgana causes the Sun to still appear the same size.
You mean to tell me the Sun is setting on the horizon of a Ball yet the horizon is perfectly flat?
Also, when the Sun passes your vanishing point you can no longer see it, even though it is the same height above the ground 3000+ miles away.
It's very easy to prove that the Sun is NOT setting below the horizon. All you have to do is when the sun is setting on the horizon, Google where the location of the Sun is over which country. Then see how many miles away that is.
You'll find that it would be impossible for the Sun to be directly over, New Zealand for instance, and be right on the horizon from your point of view. The angle that the sun should be plus it being 93 million miles away is just absurd.
Also, the reflection of the Sun over the water widens as it reaches all the way to the shoreline.
If the earth were a ball, the reflection would converge and not reach all the way to the shore since the "Curve" of the ball would be blocking the sun's light from reaching that far.