*sigh* you know what forget it. carry on.
Actually I am wrong, you are right. Voiding your quarry output is sub-optimal if you want to use its spare output for Ars Magica. And you'd want to do this becuase why the heck wouldn't you wanna slap down a quick nexus and charge up batteries with it? it's a total waste not to because that spare stuff is literally any metal you want it to be.
Still, you'd divert on site, I suspect.