> For our case, we can install the patched hyphen.cfg under luatex > specific path, e.g. tex/luatex/babel/hyphen.cfg. So other engines won't > see it meaning less risk for melting the precious latex freeze. This would be a good solution, but it's doubtful that the CTAN maintainers would allow such a file in their network Like CTAN, TL already has numerous hyphen.cfg's, so I see no impossible barrier on that front. I agree with Robin's suggestion of "disguising" it as a .dtx. Of course, Will's original point about the so-far-insuperable barriers to updating babel remains.