FenBen treatments are extremely tough to deal with the aftermath. I personally crashed my tank and lost almost everything in the weeks following treatment. I used it for blue clove polyp irradiation.... it killed um, but also took many other corals w it. As far as inverts go, yes, should remove all for atleast a few weeks if not longer. Keep a good eye out for Ammonia spikes too, and snails left in tank will surely die, thus causing that to spike bigtime. Big water changes everyday or other. Would Not add any new stuff for atleast a month or two to make sure nothing come back to bite ya as far as chems go. Chocolate chip star I would for sure wait. Also maybe research about them prior to adding one even after back stable. They’re pretty darn brutal in a reef tank, eats all sorts of corals for lunch. Hope everything goes well for you. Best wishes