My stove was installed summer 2023 and has been used quite a bit since fall. I've had some problems with it, but they were obviously related to poor dealer installation. One manufacturer QA issue: the switch for the convection fans would not turn the fans off. The fans were eventually replaced.
BK's direct support is somewhat hit-or-miss. When I call and get someone unhelpful, I call back the next day. Most of the time the second person provides better info. Usually, though, I check this site first. Support from my dealer has been poor, but dealers vary a lot.
I haven't had any problems with the air control. The stove doesn't quite keep up with heating my 1800 sq ft (14 ft ceiling. skylights, 1990s mediocre insulation) space when the outside temp is 10 dF, even with 8 hour reloads. If hardwoods were available in the PNW, I suspect it would do OK. The stove keeps up when the outside temp is in the high 20s dF. When the outside temp is 40 dF I turn the stove down to 1/2 or less air to avoid overheating the space, and do 12 hour parital reloads.
Incomplete burns happen occasionally. More likely a loading (operator error) or wood issue than a stove issue.
Once in a while I still see some smoke from the chimney after 15 minutes of wide open air with the cat engaged. My current wood supply (mostly hemlock and alder) has been stored for 5+ years (as rounds) and is generally 15% MC or less as splits, but I've seen a small number of splits of uncommon species as high as 22%. Getting those to stop smoking sometimes takes longer. Opening the air again for another 10 minutes is usually enough.
I generally load, start, wait until the cat is hot and then engage it, wait another 15 minutes, turn the air down, wait another 3 to 5 minutes, turn the air down to its final position - and then ignore the stove almost completely for the next 8 to 12 hours. The only time I make any further adjustments are in response to changing outdoor temps.