L/R differential IS useful for standing starts, but not in the way you would think. Most people (about 99%) are actually pretty even in power output for the first 5-10 strokes. They may have a weaker leg, but both legs are usually maxing out in the push/pull that comes right off the start. Where people start to get funky is right after this, when more co-ordination is needed to accelerate, coupled with riding through the banking. This is where many people will back off with one leg to try to "maintain balance" as they go through the bank. It's usually the inside (left) leg where people back off. If you have a PM that tracks L/R differential you should check this out.