I am afraid I don’t have any useful information. I was wondering whether heavier feeding might bring down the aggression? It seemed to for Green Chromis.
I do not think it will hurt although it seems to go against the grain as it relates to those wanting to keep lower nutrients.
I have successfully kept 4 Pink Square Anthias for almost three years now. I recently lost one of which I do not know why. My best guess is that after some reef restructuring I recently performed it retreated and injured itself in the process and subsequently died. The area I was working on is also the area they retreat and sleep. They are pretty sizeable and fast swimmers so that is my best guess but of course I really don't know. I do know there are no pests or disease or pathogens in my display. So now I'm left with 3.
I feed my display hourly between 0830 and 1830 dry using an auto feeder. I mix up several different types such has Hikari A, S, herbivore, PE mysis, TDO x-small, and small. Small portions, 2 drum rotations each time. Larger fish hit the larger pellets first the smaller ones get caught in the current, float around, and the smaller fish can get that. I do this thinking there are enough feedings that someone will always get something regardless of fish location and/or size. Seems to work and I honestly do not care about nutrients.
I feed frozen once or twice. One feeding happens in the evening always. I rotate through LRS Reef, Fish, Live Aquaria plankton, Live Aquaria Mysis and Brine combo, PE Calanus, and prime reef. Sometimes I will do a feeding in the morning but it isn't always a sure thing.
I feel a fish with a full belly is less aggressive. I also feel that they are less likely to nip at corals and misbehave with said full belly. I don't know but this is what works for me.
I attempted 5 Lyretail Anthias but didn't have much luck. Infighting due to a couple transitioning at the same time mixed in with a possible pathogen or parasite I missed. Beautiful fish but I won't try those again as it seems I didn't have the right number combination. Having a couple transition at the same time was pretty chaotic. That or I didn't have a large enough display.
I had success with Bartlett's back around 1999 / 2000 time frame but lost them with my display due to my lack of planning. One thing I remember is that I had a difficult time keeping their natural color. I didn't have their diet right I don't think. Fully bodied though but dull in color if that makes sense. I do not believe I was feeding as heavy as I do now.
TL; DR - seeing Anthias in the wild as a scuba diver they are constantly eating. In fact many of the fish on the various reef crests I've been to the fish are eating, bickering, foraging, and being naughty. I figured it can't hurt in a reef tank at home so that is the route I've gone. When all else fails feeding more makes me happy.
Here are my Biota Pink Squares for reference: