Same here. That said, I do imagine if you were to brew a real light lager (IE 80's EDME lager kit) with 20% sugar you could potentially get some off flavors since there is nowhere to hide. I'd stick to 10% on the BW. Before I forget, make sure you use a metric $hit ton of yeast on it. I would probably brew a normal gravity ale first and pitch on the cake and then hopefully you don't become a "my beer stalled" thread.