[XeTeX] why does Latin Modern Mono have some stretch and shrink with XeTeX ?

[Philip Taylor]

Ulrike Fischer wrote:
>
> Actually I found an old discussion which seems to imply that xetex
> calculates the fontdimens starting from the width a space -- and
> doesn't care about monospace or not:
>
> https://tug.org/pipermail/xetex/2006-June/004236.html

But do we know whether the font in question sets "isFixedPitch" true ?
Philip Taylor