Debugging gentext customizations

I'm trying to change the text of cross-references to docbook sections from
the default cross-reference text 'Section , "Section Title"' to 'the section
"Section Title"'.

I've got a customization layer for FO that works fine for lots of other
customizations (params, attributes). I've added the following code to the
customization layer:

<xsl:param name="local.l10n.xml" select="document('')"/>
<l:i18n xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0">
  <l:l10n language="en">
    <l:context name="xref">
      <l:template name="sect1" text="the section &#8220;%t&#8221;"/>
      <l:template name="sect2" text="the section &#8220;%t&#8221;"/>
      <l:template name="sect3" text="the section &#8220;%t&#8221;"/>
      <l:template name="sect4" text="the section &#8220;%t&#8221;"/>
      <l:template name="sect5" text="the section &#8220;%t&#8221;"/>
      <l:template name="section" text="the section &#8220;%t&#8221;"/>
      <l:template name="Section" text="the section &#8220;%t&#8221;"/>
    </l:context>
  </l:l10n>
</l:i18n>

However, I keep getting the same default text. What's the best way to debug
this?