[NTG-context] manual hyphenation LMTX

I may have seen a response to this at some stage in the list, but I cannot find it. \- works for manual hyphenation in Mkiv but not (for me at least) in LMTX. My general setting  is \setupalign [hz, nothyphenated,stretched,verytolerant] because I am typesetting a book for visually-impaired readers using Atkinson Hyperlegible, especially developed by the Braille Foundation. In general, hyphenation is not recommended for the visually-impaired, but just occasionally it becomes necessary. Is there a reason for LMTX is not accepting \- or is there another way to achieve it in LMTX? Julian