I have found the FE threads here to be really informative. FE was not something I ever really thought much about as it seemed so manifestly silly. And whilst it is profoundly daft it is a more or less harmless delusion (compared to things like alternative medicine and antivaxxers).
I have seen plenty of FE maps but never inspected them closely. At first glance they could be mistaken for a Transverse Mercator Projection that’s been fiddled with a bit. However, looking at them more closely they are frankly ridiculous and cannot, even with the most tortuous fiddling with the projections, bear any relation to the real world.
This is a standard FE map (I googled “flat earth map” and this was the first image in the results):
Apart from the obvious horror story that is Australia the rest of it makes little sense. The shortest route UK/Australia is via Sweden - really. I also distinctly remember flying south east from London to Saudi Arabia rather than due east.
The distance between the tip of South Africa and South America looked ridiculous and seemed to make a mockery of plate tectonics. Apart from the fact that the tectonic plates cannot be fitted to this map the presence of the Mid Atlantic ridge automatically renders the map invalid.
In the picture above I drew in the MAR in red as best I could. From the bottom point the distance (all numbers are approximate, for obvious reasons) SAF/MAR is 3100km and SAF/SAM 3300km in the real world (measured using google maps distance tool).
As I can’t find a FE distance measuring tool I used the yellow line between north eastern Brazil and Africa as a yardstick. In the real world the two continents are 3000km apart.
Using this metric and straight lines (well, why not?) SAF/MAR increases from 3100km to about 9300Km. SAM/MAR increases from 3300km to over 13000km. (The white lines).
According to the FE map the shortest distance between the tips of the two continents the green line) is about 15,000km (and to fly that you would travel NE across Brazil) whereas in reality the great circle route is about 7,000km.
I tried to fit a few other aspects of plate tectonics to the FE map but my head exploded and I woke up down a rabbit hole.