I've tried asking Stack (now Auto Meter), and they won't release the data sheet, as its their IP, which I guess is understandable... so its option 2 for me.
I have a calibrated thermocouple meter as well, so I'll be using this in conjunction with the M4, sensor, saucepan and cooker... my partner will help me calibrate it seeing as she races the car as well
I'll try and raise the temps as slow as reasonably possible... I'm only after I reasonable indication not perfection.
Cheers