My version of Memphis Dust includes a bit of dry mustard and cumin (1 tbsp each to Meathead's regular recipe), and subs ground thyme for the ground rosemary; I also reduce the white sugar by 1/4 cup and increase the brown sugar by the same amount. If it's a heartier protein, I will often add some cayenne or ancho chili powder. Meathead's recipe is really good in terms of ratios, but I do like a bit of savory spice in play.
I will note that I used to experiment with honey powder, but found it to be little more than an expensive substitute for conventional sugars; on longer cooks the honey flavor doesn't seem to last when it's a pork butt, or for a sauce that needs to come to a boil. For a sauce that isn't cooked the flavor should be a bit more pronounced.