[NTG-context] \setbreakpoints[compound] with numbers

Hi, In the texts I'm currently typesetting, I occassionaly have to deal with ISBNs. So, e.g. 978-3-123456-78-9 \setbreakpoints[compound] does not enable automatic linebreaks after or before the hyphens. Is there a way to deal with this? Perhaps something similar like \hyphenatedurl{} or an extended version of \setbreakpoints. (I currently use zero-width spaces, so I got rid of ISBNs in the margins, but a more automatic solution would be great.) Best, Denis