After digging deeper into butterfly species, I found many species such as the Tinker butterfly and Burgess butterfly to only get a max of 5".
I've also read many articles such as the one on ReefBuilders that states these species seem to be a very good choice for "reef safe butterfly's".
So it seems as if the more rare and expensive butterfly's both don't get as big as the others and are a lot similar to copperbands and pyramids with reef safety ( of course besides a little nipping here and there).
In one of the articles I read it said you should compare reef safe butterfly's to angels... which means you should expect some nipping here and there on corals.
Also as mentioned above a lot of these butterfly's only get a max size of 5". So I dug deeper with interest of adding one into my reef because of the smaller size. Here's what I came up with,
Quote - "Most deepwater species of Butterflies are less risky to introduce to reef aquariums than shallow water species, but they still may pose a threat to any polyps, mushrooms, soft corals, LPS, and even SPS. When deepwater species of butterflies are introduced into a very mature SPS aquarium with large colonies that are 5" or greater, the damage that one of these fish can inflict on a single colony is significantly reduced".
So in conclusion since these are "deep water butterfly's" they are consider around 85% reef safe (may nip at LPS not fed enough.
They've also been proven to do great in smaller tanks (as far as butterflyfish go).
Here are a few photos of them,
Burgess' Butterflyfish(Chaetodon burgessi
Tinkeri Butterflyfish (Chaetodon tinkeri)
Declivis Butterflyfish(Chaetodon declivis)
Longnose Atlantic Butterflyfish(Prognathodes aculeatus)
Marcella Butterfly(Prognathodes marcellae)
Mitratus Butterflyfish(Chaetodon mitratus)