Any one have experience with the XXV at altitude, or any of the Harman stoves? The manual spec's a draught of around .5-.6" WC at high speed and .35 ish at low speed combustion. I'm at altitude of nearly 9k and I get .4 at high and around .24 at low. I've changed the door seal, checked the pellet load seal, opened the flue up to verify no restrictions, all to no joy. Do they make a higher speed combustion blower for high altitude? any special adjustments to the control board to compensate. My installer was a Harman dealer, but to my recollection they never even checked the draught. I'm in the Golden / Boulder area if you're an installer / service guy with insight / solutions.