Kernow 1.6.1b3 does not cache the external DTD referenced in a DOCTYPE for one single pass, even if the XSL imports several files referencing that DTD.
Each imported file has the following doctype
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
The XSL imports several files using the following code:
<xsl:apply-templates select="document($filename)" />
For example, if one single pass imports 70 external files, each one with the same DOCTYPE, Kernow will still try to download the DOCTYPE 70 times with no caching.