This is completely anecdotal, but I inherited a longnose butterfly about a month ago. While it cannot eat them, it seems to irritate them enough that I have not seen as many new ones around - I usually cut them in the tank with some bone cutters and then the fish clean them up. This could mean nothing and this is just a down-cycle.
FWIW - I have some, but never enough to be really mad about them.
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