Speedotron Beauty Dish...

I shot this image of my friend AMG back in April as part of a lighting test. For some reason I just don't get this reflector or how to use it well with the Speedo 102 head. Some people say cover the translucent central disc with an opaque material; some people say place a mirror in front of the translucent central disc to reflect light back into the reflector. I only seem to get hot spots or hot rings depending upon which mod I make to the dish. Has anybody developed a modification for this reflector or found the sweet spot? BTW, mine has a glossy white interior.