You should strive to engineer a "Tight" system . What is a "Tight" system. I don't know I just made it up. But I'd like to make it mean having no greater than a .5 volt difference between any given fixture of an entire system with all voltages falling within a 11.2-11.6 volt range. You are probably saying to yourself How can I guarantee this precision when all multi tap transformers are wound with 1 volt output increments. 12-13-14-15 etc. Well I'm not at liberty to tell you right now how to guarantee this each and every project. But I will tell you it is possible and I am doing it.