Hi Errol,
When I purchased this starfish two year ago I specifically asked if it was a Linkia and was told no but was reef safe. I have never been able to find any other type of blue starfish that isn't a Linkia so perhaps he was wrong.
We've had it in our main display with no issues. Then I observed it wrapped around the base of one of the acros and thought it was munching on biofilm, cleaning it up, however when it moved on it was down to skeleton in that spot. I gave it the benefit of doubt, maybe that acro had an issue? I left it in the tank for more observation and witnessed it occur again on a healthy acro.
I put it in the 40 gal. and it may have been cleaning up the base of the toadstool but it partially detached from the rock afterwards.
I guess I should disclose this is based on my observations. I'd love to have it back in the main display but the acros are starting to really take off!
Sounds like you have a well behaved blue linkia in a nice 180 mixed reef.
Jess