Why doesn't the Loop Gear SK05 Pro 2 seem to benefit from its dual-cell setup in terms of runtime?

I was comparing the Medium floodlight modes across the Loop Gear lineup, and the runtime scaling feels confusing:

• SK05 Pro 1: 350lm / 230lm 11 hours
• SK05 Pro 2: 400lm / 300lm 8.5 hours / 9.6 hours
• SK06: 300lm 7.23 hours (single 18650)

Given that the SK05 Pro 2 runs on a dual-cell 8000mAh setup, why is its runtime at 300–400 lumens barely higher than the single-cell SK06 (8.5–9.6h vs 7.23h)?

Even compared to the Pro 1, the Pro 2 trades away hours of runtime for just a tiny bump in lumens. Is the official spec actually measured on a single cell, or is the dual-cell setup just driving the LEDs significantly less efficiently?

Would love to hear your thoughts or real-world runtime test results!