Thanks for you response.  You confirmed my hesitant understanding of
the spec regarding  line breaks; line breaking descriptions are
intentionally vague and left up to the implementer.  I've sent an
email to RenderX. We'll see what they say.

Thanks,
John

John Cavalieri wrote:
> But this is shrinking of text space to the point of being unreadable.
> It doesn't matter how much text I cram into the inline.  XEP never
> wraps and continues to squeeze the text into one line.  To the point
> where the letters are on top of each other.

Ah, that's what you meant. It looks like XEP doesn't want to break
a fo:inline. Technically, this is not prohibited by the spec, but it
is certainly unexpected behavior. You should look on a XEP specific
source for more information.
I'd like to tell you that the behavior of FOP is correct, unfortunately
you didn't tell the FOP release  you are using (FOP 0.20.5 basically
ignores fo:inline).

> Are the default fonts still the culprits?

No. I thought you got only a slight difference which caused the
last word to wrap for one processor.

J.Pietschmann