That BTA looks more than bleached.
Did it have those stubby tentacles before?
Are the tentacles sticky at all?
Does it have a feeding response when you feed mysis? As in, do the tentacles retract, bringing food to the mouth?
Or does the food kind of just lay on the BTA and easily blown off?
I've recovered a few nems from bleaching events or from being under rocks for weeks as well. But they typically look like regular nems, just without any color/zooxanthellae.
If it's eating, that's a good sign. That along with good/stable water will help it along its way.
I've fed a bleached anemone some "healthy tentacles" from a donor nem before. Whether that helped with recovery I don't know. But it was a nem with a long history so I wanted to try everything to make sure it recovered.
