Plenty to be gained on that conquest there.

Just rewatched that section through 3:25. Potential resources in the flat plane would seem unlikely to justify the trillions of $$$ spent on the vastly expensive lie.

Maybe to hide God? Somewhat more plausible if you accept that Satan has dominion over the earth, but even there I'm not really seeing the payoff justifying the expense. Although most 'claim' to believe in god, they don't really. That might blow up in major way if the whole 'firmament' thing were proved reality.

I might give you a point if you go with the god argument.