Acro Lokani Turning Green Around Base - Should I Frag?

I've been fighting off a mystery pest on this acro for a couple of months, and I just had a acoel flatworm bloom. They had been crawling around the base of this acro and presumably laying eggs. At any rate, the acros has started to turn green around the base, and the green areas are starting to flake off. I fear that I might lose the whole colony if I let it continue.

The question is, should I frag this coral before the flesh death spreads or wait to see how extensive it gets (i.e. perhaps if it was associated with acoel flatworms and I've eliminated them, the flesh will grow back)?

I should mention, by the way, this acro lives right next to an acan. They are just now starting to touch. I'm not sure if this is a stinging reaction, but the part of the acro that is touching looks fine and is pretty far from the base.