What Scandal said.
I think most of us understand how the dummy spool will allow you to get a dire vape out of a full length Prov with an 18350. But as pointed out, it's better to just keep that to yourself. Imagine the newb who buys a ProVari, but forgets to order an 18490 and has an 18350 lying around...... Sees this thread and starts gutting batteries, hacking out protection curcuits and improvising on an expensive piece of American wonderment just because he/she didn't have the responsible patience to wait for the proper battery to ship or charge.
Yes it's great that you have the ability to "think outside the tube", and if you want to do something with blatant disregard for what is proper, go right ahead. But for the sake of the 1000's reading this that could have it go terribly wrong....... It's just better to keep some ideas to yourself.