Actually, those lines
\definebodyfont[13pt] \definebodyfont[11.6pt] \definebodyfont[8.3pt] \definebodyfont[8.2pt] \definebodyfont[6pt] \definebodyfont[5.8pt] \setupbodyfontenvironment[11.6pt] [text=11.6pt, script=8.3pt, scriptscript=5.8pt, x=8.2pt, xx=5.8pt, big=13pt, small=6pt]
originated from the following issue: When using euler fonts with a text serif font let's call it myrm, myrm has a bigger x-height than euler's. So I used
\definetypeface [MyFnt] [mm] [math] [euler] [default] [rscale=0.99,encoding=default] which did the trick perfectly well.
But then, say we would like to typeset something like
$n^{n\log{n}}$
Of course, you would expect the x-height of the two fonts in the exponent to be in the same ratio as well... but this is not the case! Hence the need to tweak the bodyfont sizes as shown above. Is this a bug, or something I didn't get? Thanks, Olivier