I agree with you. The SD05 has both thermal (55°C ATR-triggered) and timed (3min countdown) stepdown regulation. Thus it will stepdown after 3min even if ambient temperature would allow to use it longer on "high" mode. Personally, I don't see any reason to implement a timed stepdown when a thermal stepdown is already in place. The same discussion aroused with the 30min stepdown on High with Sofirn's SP70.