I've also come to the conclusion that the temperature isn't so much a measure of the temperature of the coil as it is the temperature at which the juice vaporizes. We often see the temperature stall out on the SXmini, and never reach our set temp. This is the vaporizing temp of your liquid, where it stalls. Once all the liquid is gone, the temp will rise up and hit the temp limit that we set, and the voltage will get shut down. If we were heating water, for example, the coil will never get hotter than 212F until all the water is gone, only then can the coil get hotter than the water. We can apply more power to the coil, which won't effect the temperature at which water changes state, but WILL effect the rate at which the water evaporates. So changing the Joules allows us to vaporize the juice faster / produce more vapor. The temp that the juice vaporizes stays the same.
Geek out on that