Hard to tell because of the length of the smoke. Going to preheat next rack of ribs to get a feel for the difference, not to 225, just until the smoke changes from dark to light / clearer. Usually 30-45 minutes. Could also be the wood chunks.
When I cook on the stick burner, would never put meat on the smoker until an almost clear colored smoke.............just my opinion that the darker smoke during initial combustion has a bitter taste. Again, just an observation.
Take care.