DOCBOOK-APPS: chunk.xsl and DOCTYPE

Is there any reason why the solution for "Chunk.xsl produce no valid 
xhtml nor doctype" as suggested in:
http://lists.oasis-open.org/archives/docbook-apps/200111/msg00343.html
is not incorporated in the DocBook XSL stylesheets?

In general it works like suggested and could make it much easier to 
generate chunk HTML with a DOCTYPE declaration by just setting some 
variables in param.xsl.

Michael
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