Thanks for the tip Midi. I use the PTO terrain textures by default for their variety but it is good to know how to set them to the ETO type.
I am hoping that some day the terrains will use a bmp file to specify which texture set (PTO or ETO) to use with an individual tile so you could use both sets within a single terrain. Ultimately there could be a desert, snow, jungle, mountain, farm, forest, island, etc texture sets created that could all be use in a single terrain.