Ok.... I tried this.... I found my red SF diffuser, removed the reflector on the HDS Rotary, put the diffuser on, pointed toward the ground, about 6" above the ground, measured the diameter of the beam, it was about 12"-13" wide at that height, next I put the reflector back on and put the light about 6" above the ground, and the beam width was about 1/2 the diameter!. I was using a knife that I believe is 6" in length, since my tape measure disappeared earlier today.... But what a surprising result!
I had this thought.... if the reflector was held in by neodymium magnets, so you can remove it easily, and if someone made a complete flood reflector (or basically, just a bezel with a piece of glass in it, to allow max width of the beam), that would be a great combo!
Ok, you custom guys, make us a replacement bezel/reflector to swap in when we want max flood out of our HDS Rotarys!