Thanks for that link. And it's confirmed. I have AEFW
I broke the coral that wasn't doing well off the rock and put it in a small dish with about 35X the recommended dose of flatworm exit. 6 of them immediately curled up and fell off. Looking closely, there's hundreds of eggs along where the coral met the rock.
*sigh*. Expletive expletive expletive.
OK, so now it's time for a treatment plan. Do these guys eat all kinds of SPS, or are they specific to Acropora? I think I can get all my acroporids out for treatment pretty easily, but getting the encrusted montiporas will involve a lot more effort.