I am in hopes that some day a UV mapping layout like Zbrush has will become standard. Zbrush can map each polygon individually and lays them out with almost no wasted space at all. With 4 4000x4000 maps you could have a very high resolution texture over the entire figure. But it is not something you could work on by hand, you would have to use a 3D paint app like 3DCoat. But imagine how much more detail you could get into half the space for maps.