I finally did hear back from Pendleton on the Power flour. The fellow who called me is in the Pendleton flour mill in Blackfoot, Idaho. We had a nice conversation on the Power flour.
As it turns out, the absorption figure for the Power flour, 65%, is the rated absorption value for the flour, not the "operational hydration" value that I thought it might be, which could be a few percent higher. The 65% figure is rated with respect to a flour moisture content of 14%, which is the legal requirement. When I asked how the Power flour could have such a high rated absorption value with a protein content of only 13.5%, whereas other high gluten, high protein flours like the All Trumps, KASL, Kyrol, etc., had rated absorption values of around 63% with protein contents in excess of 14%, I was told that Pendleton very carefully selects and manages the wheat varieties used to make the Power flour to achieve the desired absorption value and other characteristics and specs for the Power flour. When I asked where the wheat was grown for the Power flour, he said the Power flour was milled from hard red spring wheat grown in Idaho.
When we discussed the absorption value in greater detail, he said that the 65% figure was a legitimate figure as far as actual hydration was concerned. I asked if one were using a standard Hobart planetary mixer with a 60-quart or 80-quart bowl, would one get any stickiness in the finished dough. He said no, not at all. When I asked if one could use a hydration value of say, 67%, he said that it was perhaps possible but that the typical range of hydrations for the Power flour was 64.5-65.5%.
As the photo of the Pendleton Power flour bag that scott123 posted earlier in this thread indicates, the Power flour also contains some Vitamin C and an enzyme. The enzyme is actually fungal amylase.
So, that's the story on the Power flour.