It doesn't look like the typical aefw to me either. Doesn't mean it's a different kind we don't see often, maybe it eats the slime on the coral or something. Aefw normally blend in very well with the acros, I haven't seen one stand out like that, nor have the clear look and split on its tail.
The efflo pic in your thread has two white dots on it that look like they resemble red bugs too. Could be something else but if it is red bugs eliminating them would be a huge help to the recovering acropora, especially since they are suffering with no slimecoat and such.
Look for bitemarks on everything, if there are adult aefw that,big there is bound to be evidence.