Place a ruler over a plate, and a ruler next to a ball, which leaves the suface quicker?
We are all too intelligent to point out tangents, thank you.
I understand your FE model, the one with north in the middle and south around the outside right? East is clockwise and West is counter-clockwise. This is the same as if you took the round earth, split it open and stretched it into a flat plate. Except the countries would be in different places. And compasses would read differently. And you would see forever. Etcetera.
Anyway, on to disproving your argument.
If you start in Japan and fly due east, you'll end up over New York.
If you start in Japan and fly due west, you'll end up over New York.
This may be true in a flat earth, but wouldn't it be more logical for airlines to fly in a straight line to reach New York? Instead of flying in a big circle for no reason, other than to waste fuel, time, and sell the idea that we live in a round earth?
You can't build a flat earth which meets both criteria, that being, in the case of flying from japan to new york:
1: Passing over specific countries
2: Flying east or west.
If you flew east or west, you would pass over different countries. People in the plane would notice this.
If you flew in a straight line, past the center "north pole", you would pass the correct countries, but you would no longer be flying due east/west.
You can't build a flat earth model which fits the plane travel patterns all over the world, eventually some plane routes which used to fly "south" will end up flying "east" or counter-clockwise on the flat earth in order to fly over the correct countries, or whatever.