Well, first of all, your blowers are controlled by an adjustable "blower/limit control"... if you think they're cycling on/off too often you can adjust the on and off set points (the instructions for doing so are on page 17 of your owners manual). You can set the on temp, the off temp, as well as the amount of difference between the two. I believe the "default" setting on the Honeywell Controller is 130° ON/OFF 90°, changing that to something like 160° ON/110° OFF will cause the blower to come on less often and run longer when it does... as well as keep your firebox temps higher, which will help reduce creosote formation. You may need to experiment a bit to find the best setting for your setup.
Second, aspen, (soft?) maple, Boxelder and Black Ash are not high BTU firewoods... and they don't last long in a firebox. If ya' want "hot", overnight (8 hour) burns ya' ain't gonna' get it from those types of wood. Think of it in terms of weight; the same "volume" of oak will weigh twice as much (or more) as aspen or Boxelder... same goes for the difference between soft and hard maple. A firebox full of oak will burn twice as long (or even longer) as a firebox full of aspen... and firebox temps will be much higher also. We burn "low" BTU firewoods during the daytime to maintain house temperatures... but at night, before bed, I load the box with (depending on how cold it's gonna' get) oak, hard maple or even larger chunks of elm for longer, hotter burns.
This just my opinion... but I wouldn't put much stock in the moisture meter reading.
My thinkin' is... if'n ya' haf'ta leave that draft spinner open, rather than just use the thermostatically controlled damper... your firewood (at least some of it) ain't as well seasoned as you believe. Although, admittedly, it seems the likes of Boxelder and soft maples (i.e., lower BTU, "softer" hardwoods) do require a bit more air to burn hot enough to be of much use. I've never looked at one... but maybe your thermostatically controlled damper needs an adjustment, maybe it's closing too soon.
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