[XeTeX] Underline thickness and position for Type1

[Pander]

Hi all,

Accodding to the PFA file (conversion of ASCII of the PFB) for Century
Schoolbook L, different underline thickness and postion are defined for
regular, bold, bold italic and italic. Being (in the same order) for
thickness: 61, 60, 54 and 42.

When I use \underline in XeLaTeX, the underline has the same thickness
and position for all these four fonts.

Should XeLaTeX take this into account when underlining? Or do
alternative underline methods exist (like soul package) that do comply
to these settings in the Type1 font?

Thanks,

Pander