Chris. It seems that you are steering me towards the 1:4.5 ratio.
I am planning on using the 13T pinion. With the 1100Kv motor, the calculated sweet spot is between 2,337rpm and 2,430rpm HS. I am planning on starting out with 2300rpm and 2400rpm HS. With the 1:4.0 ratio, that would yield 9,200rpm to 9,600rpm tail, respectively. However, with the 1:4.5 ratio, those head speeds would yield 10,350rpm and 10,800rpm for the tail. Ideally, an optional 1:4.25 ratio would yield 9,775rpm and 10,200rpm.
So, for HS between 2,300rpm and 2,400rpm using the the 556/96 blades, which tail ratio would be optimal, 1:4.0 or 1:4.5?