So many people have been super successful with 24/0 light that it's hard to argue that it doesn't work. But I've never seen a comparison between the growth of 18/6 and 24/0 so hard to say for sure.

Also if you're worried about the temp dropping too low, then the lights being on all the time is going to generate some heat which in turn will keep it warmer in the room than if they're off. Just a thought.