Taboo I know, but what about the Mandarin dragonet? Isn't it one of the best pod predators in the home reef? As long as you have an aged tank with plenty of pods, it seems that this would be the best defense.
I have lots of them also, but the only time I see them bothering zoas is if a zoa is on the verge of wasting away. When I pick them up from the LRS, sometimes new arrivals do not look the healthiest, but I take a risk. Those that did not take collection/transport too well and are on their way out are the ones that seem to be covered with the amphiods.
Those that are doing well do not seem to be bothered in the slightest by the pods.
JMO, but, and I have stressed it many times before and I know there are objections to its use and that is fine, I will still use it as I have for over 12+ years and kept some of the healthiest corals in a closed reef system, Iodine supplementation can go a long way in the overall well being of zoanthids. I have used it daily (Kent's Iodine-8 drops per 50gls daily) and rarely had problems with zoas. I know, don't use it, do water changes, need to test for it, whatever. I use it and everyone that comes over and marvels at my reef tanks always asks the same question 'How do you keep your tanks so healthy looking?'. Iodine use my friend, iodine use.