My understanding is that everytime there is a direct object pronoun in the imperative that it will be hyphenated. E.g. Appelle-moi would be Call me. The hyphen serves a useful purpose because only in the non-negated imperative mood is a direct object pronoun placed after the verb instead of before. Hence the similarity to the hyphen in the subject-verb inversion which is the other main case where word ordering is changed.
That will definitely be the case because of the way we are learning. I finished this tree in August, and I am just now finding the confidence to have conversations with native speakers. I find that I have to write a sentence down before I can recite it, especially if it's rather complex. N'abandonne pas ! Tu peux y arriver.