You're right, I've started implementing it. Here's the code I have so far, with the important bits in bold:
//Red Auram Implementation
# Alloying
mods.tconstruct.Smeltery.addAlloy(<liquid:red.aurum.molten> * 2, [<liquid:fairy.molten> * 1, <liquid:pokefennium.molten> * 1]);
# Block and item...