Hey! mine lived about 7 months before tragically jumping out, if he hadn't jumped out i know he would still be with me. i'd say their care is intermediate/difficult just because its hard to find a healthy specimen, but once adapted to aquarium life their care becomes much easier, my current one lives with a Cubicus boxfish and they don't bother each other.
if you were to get one here are the things you'll wanna do
1: Make sure the fish is active, eating and showing no sign of stress at the store (they will turn pale when stressed)
2: a smaller specimen will most likely adapt to captivity easier
3: Make sure to feed it a lot, similar to Filefish and Anthias, they have high metabolisms and are constantly grazing in the wild, a varied diet of clams, krill, squid, mysis, and nori is recommended.
4: Make sure his tankmates aren't too aggressive, (fish like Basslets, Cardinals, smaller Wrasses and even some morays of the Echidna genus will be fine with these guys, make sure he cant fit in their mouth)
5: be aware that he may nip your corals, the only damage any of mine did was a single torch head, but so far they haven't nipped anything else.
if you get one or have more questions feel free to PM me, i can give you plenty of tips on how to care for these guys and i'd love to see more of these in the hobby.