Hi br3ttb, in some other DIY-reflow-oven-tutorial they recommended to either directly wire the temperature sensor to the PCB you want to solder or to wire it to an old piece of PCB, which can be placed next to the "real" PCB. So not the Temperature of the air inside the oven would be measured, but the one on the PCB's surface.
Sounded logically to me, perhaps something to consider...