All things considered, it was 'almost' impossible to correctly describe mana in a form as convenient as 'MP'. As it was in ANW, it was certainly handy and easy to use. But it wasn't the most accurate.
Still, an inaccurate system of measurement was far better than none at all. And the truth was there was a true, and somewhat, accurate relationship between MP and energy production. Quite the accurate if—and only if—those with average talent were used as the baseline for comparison.
Of course, there must to be a 'true' mana to energy 'conversation'. An absolute relationship that was independent of outside influence. A constant.
For ease of conversation, Miracle's scientists refer to this as 'The Absolute Mana to Energy Conversion'. A mouthful. TAMEC for short. Described as the point at which mana was completely converted into energy.