I have a #2, so my experiences may be different. When I do BB ribs, I smoke at 235-240F for 5.5 hours and get meat that falls off the bones results every time. I take them out at 4 hours and sauce them up, but they are definitely not ready at that point. Another 1.5 hours back in the smoker works for me, consistently.
The cook time instructions were developed quite some time ago, and I am not sure if the 3D even existed then. Perhaps the digital models have a different cooking time because the heating is more stable than the analog models?