https://wiki.tfes.org/Equinox#A_Flat_Earth_Equinox
A Flat Earth Equinox
Q. How can the sun rise from even within two degrees of Due East in the Flat Earth model?
A. This is a popular topic point, but is based on a common misconception. The top down views of the Flat Earth sun models might imply that the observer can see infinitely across the earth, and see the sun at all times. However, we cannot see infinitely into the distance. The distance to the our horizon is limited to a very finite circle around us. We cannot see that far.
But whatever anybody says we can often see the sun quite clearly at sunrise, like this:
 Sunrise - Black Sea HD, kalcymc - sun part risen | |  Sunrise - Black Sea HD, kalcymc - sun risen |
I have some similar photos but they are taken just after the official rise because I don't have a view over a clear ocean horizon.
The equator circle has a radius of close to 10,000 km.
Hence from anywhere south of the equator, as I am, at either equinox the sun must be over 14,000 km from the observer - simple geometry.
Since that is undoubtedly the distance to the sun and we see it rising we obviously can see that far.
The distance to the horizon is limited by the thickness of the atmolayer. The atmolayer is not perfectly transparent. At night when we look out at where the sun would be across the plane of the earth we are looking into hundreds of miles of fog, and thus the sun is dark and unseen.
The "distance to the horizon" might be "limited" but that limit obviously does not apply to the distance to the sun.
Beneath and around the sun is a circular area of light, which represents day.
No, if you check the illuminated area of the earth at the equinox it must be a semi-circle and cannot be a circle.
On a rectangular map the illuminated area for a September equinox looks like this:
Day and Night World Map Sep 23 2017The rounded corners of the day-night transition are partly because the time of sunrise is defined as the time the sun's top "edge" first appears and disappears.
Then the day length is lengthened a little near the poles because of about 0.5° of refraction at the horizon.
That night-day boundary can found from either Timeanddate.com or simply checking at an equinox with people across the earth.
The simple "geometric area" that is illuminated by the sun on the Ice-Wall map has to be something like this:

The sun is projecting its image upon the thickness of the atmolayer around it (see Magnification of the Sun at Sunset). This image of the sun upon the atmolayer has been colloquially termed the apparent sun. Along the edges of the suns circular area of light is sunrise. When the circle of the sun's light intersects with the observer's personal circle, or "dome", of vision, sunrise will occur for that observer.
During Equinox the sun is over the equator, with its circular area of light pivoting around the point of the North Pole.
Sorry, there's no "circular area" and I suspect that the claim of circular area is no more than an assumption.
The points on the edge of the sun's circular area of light are tracing along the latitude lines, the time of the Equinox being a circle pivoting around itself.
Why is that even slightly relevant? The light from the sun does not travel "along the latitude lines". It travels in near straight lines to the observer.
Further, the circlular latitude of the equator is very large,
and if one were to zoom into a segment of that circle, down to human standards of an observer's small circle of vision, down to a town/personal scale, the curve of the equator beneath the observer would straighten out. The latitude line beneath you locally is relatively straight.
Again that is not relevant because the sunlight does travel along those latitude lines.
From where I live, at sunrise the sun has to be over 14,000 miles and the geometry would look like this.
Ice Ring Map - Sunrise Equinox AustraliaNow if the sunlight travels in very nearly straight lines the Ice-Wall map would indicate that the sun should rise 37° East of North but I know that it rises due East, at least within a degree or so because that's the best I can measure direction.
When the edge of the sun's area of light intersects the observer's circle of vision it will approach from the East, or near the East.
Possibly ly it might, but that bears no relation to the direction the sunlight appears to come from - that is the straight line from the sun to the observer.
The apparent sun at sunrise is on the rim of the sun's area of light and is racing upon the atmolayer along the observer's latitude line to the observer. However straight the observer's latitude line is in his or her local area where the observer can see will be how close to East the sun will appear in its initial bearing.
Consider the following:
If there was a race car (or jet ski) racing along the surface of the earth to you on your circular latitude line, and you only see it when it is nearby, would you see it from the East or very near the East? If so, then that is the answer.
That analogy is meaningless because the jet ski or racing car could be see for only a short distance but the sun can be seen when it's my thousands of kilometres away.
So if you expect anyone to be convinced by that Wiki entry you need to provide evidence that the sunlight can curve around the latitude lines like this.
And you have not done so.