[docbook-apps] chunking and chunkfast

I am upgrading docbook xsl stylesheets from a pre-version
1.56 to 1.69.1 and I came upon a timing issue with my builds.  My biggest
build went from 4 hours to 9 hours. This is unacceptable so I started to do
some digging and discovered the chunking was reworked at 1.56.  Turning on
the chunkfast parameter does not seem to be working.  

 

Does anyone have a working example of how to set up the
stylesheets for chunkfast?  There is an example in Docbook XSL: The
complete guide but it does not seem to address chunkfast in the example.

 

I also found a statement that says the new chunking is now a
two step process.  Is there anyway to get around this to try and save
time? 

 

Thanks,

Joy