It just isn't. Morphs are pared .OBJ files and .OBJ files assume their coordinates are already correct, hence they store no scale correction values. This leads to the second point. If I had to guess, messing with Scale in Poser (and probably Taper as well) doesn't fundamentally alter the internal mesh data Poser keeps and it exports the original values instead of the scaled ones. (perhaps CuriousLabs could fix that) OTOH if you opened the .OBJ in a 3D editor and did the scale there, the actual mesh data would be recalculated and the resulting morph would show the scale (but when you apply it in Poser, the scale will still read 100%). I've created wonderful full-head morphs, saved the original figure, then applied the morph to another of the same base figure and it's looked...wrong. Custom scales not retained is why.