480p -> 2x240p (duplicate every other line to bypass interpolation for e.g. GC GB player)
I can see how this feature could be useful, but I’m not sure it’s useful for the GameCube GameBoy player, since that can do native 240p output without interpolation via either Swiss or GBI.
EDIT: Yikes, that blockquote is enormous. But I didn’t specify any size for it…