So, in compounding does one burn the power stored inside of a metalmind or does one burn the metalmind itself. In Alloy of law, Wax claims that Miles needs lots of gold for his constant compounding, this leads me to believe that its the latter; at the end of Alloy of law, it says that they removed all of Miles' metalminds so that he couldn't heal himself. I'm just a bit confused, and I have only read era 1 and Alloy of law.