Mike, I just use the draft flap on the fan motor to control the amount of air into the firebox for the needed heat output. I adjust the flap to full open or almost closed, depending on the outside temperature. Want it hotter, open the flap. The main difference I see between your 1557 and the 1600 is that you also have the ability to let air in at the feed door too. The 1600 doesn't have that option.
After a while of using my Clayton, I was able to tell were to adjust the fan motor flap to the outside temperature so that the fan motor didn't come on until the natural draft was insufficient to keep the temperature, because the fuel was getting low, or only came on when reloading. The thermostat does its job of controlling the motor well, to the desired room temperature, when burning wood in the Clayton. The motor should be able to get your fire going hot enough to set the 200 degree fan limit off to the combustion draft motor within 15 minutes or so, depending on the moisture in the wood and the stage it is burning. Yes, the circulation blower may cycle on and off. It really depends on your fan limit settings and your demand for heat as to when the circulation blower will cycle. I just noticed that once you find the sweet spot for your stove in your house system, you'll always get the same results.
With a clean chimney, I would consider making one short hot fire a day, say 10 or 15 minutes, to burn off any creosote that may have accumulated in your liner, from burning only wood, and keep it clean. By doing that, I was able to lengthen the time between brushing out the chimney, bottom to top. Just a thought.