Actually, on a flat plane you cannot "see forever" but your horizon is the same as on a round earth of the size commonly put forward. Complete with increasing height making the horizon farther away. However, when you use high-zoom cameras in real life, it turns out
MrRoboto, the definition of the horizon is where light rays form a tangent (grasing)) the earth's surface before you seeing them. not how far you can see because of fog.
Using binoculars, you can actually see a ship's funnel appear, then rising , and then fully climb over that "hump" in the distant sea. see?
On a clear day , night really, we, (the Austr-aliens) can not quite see forever, but 2.5 million light years away, to Andromeda, by comparison, to the end of your flatland,s edge, it's horizon, , it's a mere 1/24 st of a second. With the right magnification you can see light from 13 billion light years away all directions even from the top and the bottom of your plate.
what a waste of time and talent for you to rise to the defense of the indefensible. remember what Jesus said about the wasted talents? the bible is a book written by flat earthers, this is not the place to defend that. but ,
iron sharpens iron, for what it's worth.