Sam: Don’t be obtuse. Kadur is a ball. Rashi says it’s a ball (“pelote” in French). The statue is holding a ball. I don’t what the ocean being a plate is, but I do know we’re being told the olam is a ball. In any case, you’re making it like the story with Alexander is coming to limit the prior statement that the olam is a kadur, which it’s clearly not doing.
By the way, when you said in your first comment on this topic, “It’s Kefirah to say the world is round”, which part of the Yerushalmi were you accusing of kefirah?