Only on occasion, not reliably at all. Maybe 4-6 times where I've actually watched it do it. Flames lightly appear, disappear, reappear, not even really sure it's a backpuff. It's just that they're filling the whole firebox and then they completely disappear. Nothing like the explosions I used to get before which were clearly back puffs.H rmm. How often is this happening? Because backpuffing will blow smoke in your house for sure. Suggests poor draft still or wet wood.....
Definitely not wet wood, at least not the main reason, as most of my wood is dry. Nothing is above 20% MC, most is pine and well below that, and I still get puffing and smoke. Never a stalled cat though...