As of the end of November, the boat dock was closest, followed by the taxi and Minnie Van drop-off. The Uber/Lyft drop-off was next. The buses were farthest, but the distance can vary quite a bit by exactly where in the the bus loop your bus happens to unload; it could be slightly farther than Uber/Lyft, or 600' farther. The bus unload position has nothing to do with the assigned load zone for your resort.
I'm not aware of any changes since then, but I haven't been there since.