Newb alert: few questions

[Cyparagon]

if one is focused better would the power reading not be higher?

No. The power density (power/area) would be higher, but the power is constant.

I am asking how you can measure a green laser and get the same value when you measure the purple laser (not at the same time) on the same meter if green for example heats the sensor by 20 degrees and the purple heats it by 25 how could they possibly have the same power reading?

The coating is generally carbon based, so it is designed to absorb all light pretty much equally. There will inevitably be some materials that green burns better, too.

No one is saying violet is always better at burning in all circumstances, just generally.