Per KMF's instructions, made the following changes to Stow rendering:

• Fixed a bug where editorial notes were not being included at the bottom of the page, although they were clearly there in the XML. This is rather a strange thing; it seems to recur sporadically for no good reason in the live site, but not in dev. I'm at a loss to explain what makes it come and go, but at the last test it was working fine, and the live and dev trees (XSLT and XQuery) were identical. We'll have to watch this. It appears this is due to a bug in eXist's parsing of a generated in-memory XML document; I seem to have worked around it by making paths like this: $dataDoc/descendant::text/descendant::note into paths like this: $dataDoc//text//note.
• Increased default line-height in prose paras.
• Added a default top margin for line groups.
• Set default rendering for head elements to 200% font size and centred.
• Tweaked the CSS for the page navigation at the bottom so that it doesn't overlap with forme works. Did the same for the footnote block.
• Fixed a couple of encoding errors in Stow.

All of the default rendering settings will of course be overridden by any @style or @rendition settings in the XML itself.