T&E isn't double insulated cable in the true sense of the definition. Nicked cables, or squashed, pinched, crushed cables, or intermittent faults due to foorboard movement maybe rare, so it's all about risk management. Anyway, all I'm saying is that a decent quality volt stick like the Fluke is small, light, clips to a pocket and can be kept about the person all day without any trouble. Seems to be no good reason not to carry one and have something to hand which is pretty reliable.