I'm no expert on wood burning stoves but I have run a few different ones at different times in my life and I hang out with some people who are long time burners. One of those people sometimes reminisces about a Vermont Castings Vigilant(?) he once owned that was set up to gradually open the damper as the stove temp dropped later in the burn. So if that works, and it apparently did for Andy, why don't more manufacturers design and sell stoves with such damper systems installed?