Use Mallard as source for man pages?

Hello,

the Glabels project [1], which resides in the Gnome Git repository for
years, is currently to be ported to Qt5 [2]. Because the user
interface is similar to the old GTK one, we want to reuse the existing
user manual (at least partially). So Glabels-qt could become the first
Qt project which uses Mallard as source for the user manual. Luckily,
neither itstool nor yelp-tools seem to have any hard GTK/Gnome
dependencies, which makes it much easier for a pure Qt project.

Besides that, we want to reuse and extend the existing manpages. Groff
itself is not very attractive, so we are looking for a simpler way.
Markdown came closer, but it seems to be no more than a "poor man's
XML" and almost unusable regarding i18n. Docbook is too complicated in
comparison with Mallard, so the latter could be the less painful way,
if possible. Would be nice if we had the same syntax for both user
manual and traditional man pages, wouldn't it? Moreover, we can use
the mentioned itstool/yelp-tools for both without bothering with
different tools.

Essentially, we need a proper way to convert Mallard to Groff, using
an appropriate stylesheet. Any help would be very appreciated.

[1] http://glabels.org/
[2] https://github.com/jimevins/glabels-qt

Best Regards