Thanks for the well-wishes and advice Bulldozer, much appreciated bro.
Yes, Harlequin Filefish are undisputedly in the higher tiers of the more difficult-to-keep fishes. This is due to 2 factors. The first is that they are obligate coral feeders, and are difficult to wean unto eating prepared foods. The outcome of this is the unfortunate event is usually death by starvation. Also, these filefish are extremely shy fish, slow-moving and extremely vulnerable to attack by more aggressive fishes usually present in most reefers' aquariums. Thus, the slow moving filefish are susceptible to being bullied, might die from excessive bullying, plus the existence of the problem that they are not able to feed enough to sustain them as they are very, very slow eaters.
I plan to keep the fish in a pair, in a proper sized tank where they are the only fish. I hope that I can get a specimen that is already feeding on prepared foods and will only try to keep these fish if they are already feeding, as the responsibility of getting them to feed is mine, and I do not excel in getting fish to feed on prepared foods.