The holographic wall around Esthar is a physical barrier, made of variable camouflage plates.

The Ragnarok seems to fly 'through' the barrier, but the World Map is not drawn to scale. If you fly at ground level, it doesn't work (so far as I recall). Obviously, the ship is actually going over the barrier. The barrier has a finite height, after all; it isn't an all-encompassing dome.

The Garden can't even get onto the Esthar continent, so the entire debate is pointless. The Garden CANNOT land on Esthar; that continent has no beaches.