There are many cases where an element in an xml file matches instructions in both book.xsl and collation.xsl. These should be cleaned up so that collation.xsl has exactly what it needs without being duplicated in book.xsl. More work required to see how feasible this is.
I've eliminated book.xsl and replaced it with minimal.xsl and minimalOverride.xsl.
I've cleaned up collation.xsl and eliminated all redundancies with the two new files.
There are many cases where an element in an xml file matches instructions in both book.xsl and collation.xsl. These should be cleaned up so that collation.xsl has exactly what it needs without being duplicated in book.xsl. More work required to see how feasible this is.