I know that SLIPA is a first go around at making an IPA table for signed languages, but how comprehensive is it? The creator freely admits that his main exposure to sign languages is ASL, which worries me: as an analogy, creating an IPA based on West European languages would omit phonemes such as the pharyngeal fricatives and neglect click consonants, ejectives, and phonemic tone. Especially given signed languages' tendencies to be language isolates, I can't imagine that an IPA based on mainly on ONE sign language could possibly capture everything phonemic in signed languages.
Hence, my question: how comprehensive is SLIPA? Are there individual signed phonemes or even phonemic classes that it misses?