You probably need not MDL, but LIE presets for overlays.
I was just mentioning above that LIE materials that shipped with Amelia for Dawn didn't work with I-ray when I tried. I loaded one of the make-up presets for eye shadows that use LIE, and it rendered flat black in I-ray. From that I assumed LIE wasn't compatible with I-ray, or at least not the LIE presets that ship with Amelia.