Update on this: the frag is doing well. I moved it into brighter lighting - it's now near the top of the tank, near a Kessil 360 that gets to 100% for a few hours each day. I estimate that at max it's getting 300-350 PAR. It gets a lot of flow here too - at max, my tank nominally has 200X flow (but I don't run it at max for long; I have several random settings which go up and down during the day).
Now its color is consistent, and there's no browning. I believe it's also growing.
(it's the green one closest to lens. Not the red monti cap below, nor the green slimer below )
Problem with the pichoni is that I'm blasting it with too much light to fit a coral from "below 30m". It may also be getting too much flow for a "protected slope", but I somehow doubt it. Maybe gentler flow might work for a real pichoni. Or, maybe the scientists have not covered all pichonis. Or maybe I'm just wrong in my ID.