> you can only do kerning for glyph pairs in the same font of 256 glyphs. So
 > for building a good TeX font, you would have to build a virtual font based
 > on several PS fonts, adding new kerning information.
the only relevance of this that I can see is if you want to kern
between characters from expert and non-expert versions of the font. If
you look at the  `PSNFSS' font sets, the expertized ones already have
virtual fonts combining the two raw originals, and kerning can be
done. no problem at all

 >   The second question, which I discussed, is how supplying the information
 > one would normally expect from TeX's full capacity. This takes quite some
 > effort to add, Robin Fairbairns said.

You persist in equating features of Computer Modern with TeX itself;
they are quite separate things!! It _is_ true that you need extra
metric information to build good math metric files for TeX, but thats
another issue. Y&Y add extra detail in the AFM files for Lucida Math
for this reason.