I personally don't think that IP66 is waterproof enough for caving; they only start being tested with full immersion in water at IPX7. I don't like ports on the outside of lights (USB/charging) because I don't trust that they'll stay closed and watertight during a caving trip. I suspect these ports are why it doesn't pass IPX7 standards.
On a different point, the light steps out of turbo after 10 minutes to prevent overheating. More modern light designs detect overheating rather than relying on a timed stepdown.
It also weighs nearly half a kilo!