6P is old news: 5P is the hot new instructions density. I manage to squeeze out  a reduction of 0.2 rate by squeezing every last drop of quicksilver from each gold atom I send to the output chamber. The irregularity of the exchange of metals definitely tried to offset the gain, but once I hit 15 rate with this new method I just had to find a single cycle of optimization in the creation of five products to bring the rate down.