Just to be sure I understand. . .Your display tank had a Marine Ich outbreak. The fish were moved to a QT. They were all treated with Furan-2. Then they were given a treatment with Cupramine. Is any part of this wrong?
How long did the Furan-2 treatment last?
How long was the Cupramine treatment? What was the copper content during treatment?
Furan 2 is a rather aggressive mix of ingredients and would likely have stripped the fishes of their norma flora (the kind that should be there) bacteria. The copper would have prevented normal recovery from the Furan 2 effects. This could end up with fishes that exposed to a wide variety of what are called 'opportunistic' pathogens -- things that attack life forms that are weakened or reduced in ability to fend them off. The most common of these are the 'fake' fungal pathogens. They are 'fake' in the sense that they give the appearance of being fungal, but they aren't. REAL fungal infections are almost impossible to treat in ornamental marine fishes.
I would not proceed on the above assumption. I'm not certain yet of the diagnosis. The photos are just not clear enough for me to make a more certain evaluation. Either I need better photos or an excellent description of what the growths look like. Do they appear to like cotton? Do you see filaments? Are they identically pointed-sticking out or in a mix-mash arrangement? How thick are they? (like hairs, or thick like worms)? I'm concerned about what you call 'abbrasion' since this has been applied to different conditions on your fish. Describe what you think is an 'abrasion.' Generally, Furan 2 is given to fishes with a difficult topical infection rather than what most would call an abrasion. Is this area cleared up now on the Trigger?
I'd like to have the current test kit (not dip stick or badge) readings on:
ammonia
nitrite
nitrate
What fishes are being kept together right now? in what size aquarium?