In the end there is no reason you need a world of 6400 km by 6400 km. You only need to have that the player has the illusion/thinks the world is of this size.
That is an interesting concept. So there would be a scaled differential? I can make it seem as though it was 6400 km x 6400 km when in actuality it’s somewhere around 640 km x 640 km and everything is scaled down by 100 to make the proportions seem like it’s the same?