> Adding more invalid hyphenation points only happens if you use an incorrect > (i.e., a too small) value for lefthyphenmin and/or righthyphenmin.
I do not profess to know anything about the hyphenatiion algorithm, but this statement suggests to me that inconsistent ("incorrect") combinations of hyphenation settings should be diagnosed. This kind of arcana should not have to be kept in mind, even if it's documented somewhere. Doug