Yes, I agree here! I had an undulated just about 20 years ago and it was a very cool looking fish... but every bit as EVIL!
Right now I've got a niger trigger in my DT and it looks terrific. Doesn't pick at any corals, inverts, or other fish. Very pretty fish and a great addition.
In my attached 75 gal "lagoon" I've got an assassi and a humu and both are 3-4". They need to be fed well to stay happy so they are both quite fat. Despite this, they will [probably] kill anything I add to the tank unless I do it very carefully (they do leave the established fish alone). They do not touch any corals (soft, LPS, SPS, gorg) but will happily eat any inverts obviously. This is the only thing keeping me from putting them into the DT. They will look so good in there some day.