You put in values you think will be safe as a starting point (based on experience) then you get the AFR's right, then you increase the ignition until you hear det, then you come back a few degrees.
Thats how you do a basic live map anyway.

Things like minimum advance for best torque need rollers, although generally taking timing out till the heat increases (if you have an EGT probe and can hold it on the brakes or similar to load it on a cell for a long time) gets similar results as normally as you move from min advance for best torque you also see an increase in temp