Oh ya, no doubt the change in lights was a catalyst, but not the source or everyone with LED would have cyano. It feeds on nutrients, so as long as you manage what goes in, the nutrient it's using will be a limiting factor and once it's consumed, the slime will disappear. I know it's tough, and I've never had to have the long battles, but I would still never add chemi clean, primarily because they won't tell you what's in it. I won't add mystery juice to my tank just on principle
Keep battling, turn the lights up, and one day you'll have forgotten that you even dealt with cyano. With the lights up, the corals will start competing for nutrients, which will help the battle.