you're making it very clear that you don't even understand your own diagrams. probably that has something to do with why you believe they are accurate.
the line i drew represents the distance from an observer arbitrarily placed in America to where the diagram claims the position of the sun is at sunset.
sunset and sunrise is absolutely impossible in a platter-planet model. however, sunrise and sunset are Biblical terms and readily observed trillions and trillions of times every month by billions and billions of people. in order to give the appearance that FEN deals with the direct contradiction of evidence to their narrative, FEN claims ((without any viable explanation)) that at a certain distance sunlight simply curves away and disappears. a certain distance that happens to exactly coincide with the curvature of the earth in a heliocentric model.
the existence of observed sunset & sunrise determines this distance ((i'm leaving out the fact that determining this distance by observation while assuming the earth is a frisbee leads to all kinds of contradictory results, if you take various locations and compare them - instead, we're starting with the simple case of one arbitrary observation. if FEN is true, all observations should match - they don't of course, but that's a bit beyond what i expect you to be able to comprehend at this point. basics first.))
flat-nonsense claims that at this distance, and every distance greater than it, an optical illusion prevents sunlight from travelling in a direct path to that observer. thus the sun appears to set, and it is dark at that location - according to this nonsense model - and dark also at any location where the distance to the sun is at least this great.
so take that same distance - the distance at which FEN claims sunlight cannot reach - and apply it to the diagram you claim is accurate.
that makes all of Australia perpetually dark for at least half the year, and likewise ((though at opposite seasons)) all of America dark perpetually, and a great part of Alaska & Canada should never see daylight, ever.
obviously, there's something very wrong with your explanation.