Andreas,

> Question: Is there any reason why HostFont has to be in the m17n image?

  The main reason is that I do know it requires some more fix-ups, and
if it is there, I'd hear the complain earlier so I'd be inclined to
fix it earlier... so the goal of putting it in the image sounds like
satisfied.

  I kind of like the idea to make HostFont accessible to the users,
but not strong feeling here.  And the plugin people use and the code
in the m17n image are imcompatible at this point, so it would be
better to back it out.

-- Yoshiki