The temp of the engine is not a factor. It's adjustment based on the temp of the air drawn into the engine. As the resistor is in series with the sensor, the value still changes according to the temperature read. The amount of fuel increased is very minimal, in fact the duty cycle reading of the injectors is hardly changed, if at all. It's apparent that the stock value is too lean on my car as the ECU value believes the air is hotter than it really is, hence the leaner mixture applied. Adjusting the value just until hesitation stopped, whilst driving, then checking the incoming temp values after using ECU scan afterwards matched up.
I know the common answer from many is to suggest a remap without actually knowing what was done in the remap, which is fine, if it works. All I know is that simple mod works on mine great. To date I had tried different exhausts, modified induction kits and ECU resets with no luck.