I lost two tinny frags, but I think my urchin broke them off :lol: IMO if a coral is lost to this method, there must be something unseen that leads to it's demise. Maybe something nocturnal has done the damage, who nows? but not as the result of lack of light.
I think the lights out idea only replicates nature in a way. Think of a big storm over the reef, it may last a few hours to a few days, so it happens in nature to have lights out in a manner of speaking. I find this the most effective method for beating cyano. I tried chemicals when I first started, but I learnt to address the problems, which I believe is primarily nutrient export.
I've read that to survive cyano needs light, nutirents, poor water flow and temperature's above 18 Celcius. Obvioulsy we can't change the temps, water flow is easily fixed, but doesn't remove the actual food source of cyano, just moves nutrients to other area's. Now the light can be cut out which works, but if the nutrients are still in your system, the cyano will come back, and it doesn't need much to come back, hence the big water changes in the outlined method.
I don't believe increased flow fixes the problems, because once solids are broken down, and if not skimmed out, then they fuel nuicence algae's and cyano, But this just my opinion.
So I think you need to look at the amount you feed, types of food, and your husbandry. Are you getting good skimmate? and if not, are you doing regular water changes? These little things will add up to cause problems. Even in a mature tank it can come back.
I'm a big fan of water changes, especially in the early stages of a tank's maturity, as I believe this is the best way to get nutrients out of our systems.