Acclimation shock typically sets in within a month, and I do mean...a full month...and is characterized by disintegration or melting or white patches developing.
After that, the next "success" point is about 12-18 months, when many will die of starvation in tanks without enough rock.
Otherwise, looks like a good specimen
YOu need to keep those pictures, see how fat and cylindrical the arms are in the second pic? That is still a reasonably well fed star. Refer to those pics every so often.
Lots of LR in a big mature reef tank...that's part of the key