Re: Blindstaring on descendent(-or-self), following(

<xsl:when test="$current-node/node()[1][self::text()]">
     <xsl:text>NO TAG, JUST TEXT, WRITE FONT_DECL</xsl:text>
</xsl:when>

... but given your case, don't you want the font_decl *any* time you have a text node child (even in the middle or at the end)? So "$current-node/text()" would be the test?

If it passes the test, I think you probably want to shift into a special mode:

<xsl:template match="*" mode="font-wrapper">
<xsl:template match="text()" mode="font-wrapper">

In any case I suspect that even if this doesn't do the trick, a special mode offers you a much nicer and more general solution to your problem.

Similarly, I wonder if you really want or need a function to do this. In XSLT we can "micro-pipeline", using templates to process the results of using templates; the function looks to me like it's only adding extra overhead.

Please forgive me if I've understood the problem incorrectly.

Cheers,
-- Abel