I never allow my tank temp to exceed 80 degrees. I have quite a few zoas and I try to keep my tank at 78 normally. If my chiller struggles and the temp surpasses 80, I freak out!
I have a tank in my backyard and temp go as high as 87 and everything all the zoas i put there do awesome. If they look sick in my main tank thats always at 79 I put them outside and most of the times they come back.