If the sun is a spot light that shines down from 3000 miles app, and it disappears from view do the perspective and the limited penetrability of the atmosphere, Then the sun should come in to few fairly high in the sky and appear as an ellipse that gradually gets brighter, larger, and more circular as it gets closer. If you were not sure what I mean, take a look at a desk lamp that is shining straight down on a desk. Align your eyes near the surface of the desk (on your hands and knees?) but across the room, then move toward the lamp. The sun does not look like that at all. The only way it could look like a circle when it first comes into view is if it is shining toward you. Then I would have to slowly rotate always staying toward you. That couldn't happen all over the world for everyone at the same time. That means that the sun has to be a ball, because a ball is the only shape that looks like a circle from every direction. If it is a ball, then that creates issues about why we can't see it from high-altitude flights on the far side of the flat earth.
The thing that's maddening about this site is that a large and frustrating fraction of the participants don't care about logic or meaningful observations. Maybe it's just completely pointless continually bang our heads against people who reject math, science, logic, reason, and simple explanations about why nothing about the flat earth model works beyond the most superficial things. Their whole argument seems to be "it looks like to me." If I had a carpenter, or a plumber, or an engineer say, "I don't need to measure this because it looks flat to me," I'd fire them and move on.