I believed that using progessive loading false and auto would mean that you should only load the cubeface used for you initial view.
But this seems not to work this way. It only works as you proceed with panning.
For the first view I load 3 levels even if only level 3 is used. That means I have to download from 1.5-2 mb unused tiles.
In reality I could make the full pano with just 2 mb download for the full panorama with a size at 2048x2048 and no mutiresolution.
Hans