This I can see. I was of the understanding from what I was told the reason they don't want "too dry" of wood is that a lot of the combustible fluids responsible for creating the off-gassing fuel somehow evaporates with the water. This then leads to not being able to make BTU's. I just don't buy it. This is the complete opposite of what you are referring to. I'll never see my wood under 10%. 12-14% is about the lowest I'll see. Explanation:
Two words, stack velocity..... or maybe just residence. My bk moves such a small amount of air i dont think this is an issue.
My wood spends 6-12 months or so in the open under top cover tarps. Then a year in the shed. Then about 6 months in the basement. Here pics of both halves of a piece of red maple from the basement. Fresh split. Probes inline with the grain. I guess my "combustible fluids are gone and I'm burning toilet paper." Oh well, my Max Caddy likes TP as much as the country did during the first month of C19!
I just tested a re-split of a large split of red oak last night before loading it. I got almost 19% on the same meter you are using. This has been stacked for 6.5 years!! My stacks are top covered and on pallets....in the woods though, so they don't get much air or sun, except in winter, when we don't get much sun period and the air is cold. I hear ya, I don't have any issues either burning the dry stuff in my Kuuma.
Red oak vs. Red maple is likely part of the difference for sure. Plus, for the last 6 months when my seasons worth is in the basement, I have a dehumidifier running for normal basement humidity. I'm betting it's helping dry out the wood too...