Only the peppermint shrimps aren't the reefsafest.
It's been told they pick on tubeworms and go sometimes on soft corals.
That's the reason why I didn't buy one despite the fact that it would even socialise with my cleaner shrimps as they are both Lysmata species.
And my Aiptasia look exactly they same. Simple tests for them. Molest them with something like a turkey baster or so and they will fully retract into their hole so you won't see anything at the end.
Only someone mentionned they would spawn even more offspring if molested.
I don't need to panic as my tanks are small and simple to control. Among my button polyps I spotted a small Aiptasia thing and prepared for action. But when I looked closer to it then it was only a light pink feather duster.
With a magnifiying glass I spotted another tiny feather duster, too, on this rock.
So, my tanks aren't that big that they spread and I don't become aware of them.
But in a large tank with much rockwork they can become a pain to remove.