well, I hadn't considered making more, but I can get parts to make 2 or 3 just like it.
the idea about having the 3 buttons produce different voltages isn't really feasible, but I can put a boost regulator in there to make it a VV mod, but that would double the part count and the cost of building it.
edit:
I was thinking just now, and I'll bet I could fit an 18650 in the original battery compartment easier than modifying the whole thing to use a big, not-user-changeable flatbatt.
I guess this would be a plus If I were to sell them.