I have some brown button polyps with fluorescent green centers. They do get big. They also reproduce quite rapidly. I like 'em. Yours look nice. Is that about 2" diameter with all the tentacles?
my xenia did that the last time I did a three day lights out. I was about to tear it out and throw it in the trash, then it made a miraculas recovery overnite.
All of my leathers get that harded dark stuff on the bottom before they shed. I got a few scarlet hermits and they love to eat it off without hurting the leather. I think the lights being off for so long was your problem. I think they will drop the weak ends of and the s--t will be all over your tank. We have so much of it in are area you can't even give it away.