cursed RTF outputs

It seems I am stuck in 2004 problems.

I am trying to get an RTF-compliant output from XSLT (3.0) but as usual,
like back in the old mailing lists, characters aren't coming through. Has
this been solved with a particular encoding yet?

My test situation is with this node:

<node>C) C( C  B( B0 C.</node>

And this stylesheet using output encoding Windows-1250:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="3.0">

  <xsl:mode on-no-match="shallow-copy"/>
  <xsl:output method="text" encoding="Windows-1250"/>

  <xsl:template match="/">
    {\rtf1
\par <xsl:apply-templates/>
     }
  </xsl:template>

</xsl:stylesheet>

I get an rtf document with these characters

C ? ? B$ B. C4

Many thanks in advance,
Jean-Paul

PS: incidentally https://xsltfiddle.liberty-development.net/6qLYEp2 even
says it won't output because the characters are unsupported. So this just
adds to my confusion about how to make any of this work.