Well, we *can* load balance the multiport right now.. the display just won't be updated and half the people would be asking "why am I getting coin X when it says the multiport is on coin Y"

But regardless of that, it would still be a tough call to mine something other than WC at the moment. Those are the toughest calls we make at ipoMiner actually.. when to stop mining a guaranteed win to mine something that /could/ be better.