We have a gold flake (as well as blue face, regal, flame and potters angels (and other fish)) in our reef for 2+ years and the only casualties we have had were zoas (although they all seem to leave palys alone as you can see in the pic below)
. As you can see from the varied responses to your question, a lot of the "reef safe-ness" comes down to individual fish and we all take a calculated risk when we introduce a reef-safe-with-caution fish into our tanks. For us, we planned on this type of a tank as my wife loves many of these fish so we started with the intent of having an SPS dominant tank to increase our odds of success. Our other tank is much more of a mixed reef and we absolutely do not introduce reef-safe-with-caution fish into it. It all started when we were only planning 1 tank for our new house and when I said we can't add some of the fish my wife wanted to she asked why don't we just have 2 tanks....and you can bet I was on that in a heartbeat!