This is a quick patch to add support when strictWordStyles is true:
Edit the file HTML2WordML.inc and in line 1949 (after the 'if (!$this->strictWordStyles) {') add this:
 else {
 $stringListPr .= $this->pPrSpacing($properties);
}
This got me very close to what I was after, thanks! I did not need to style the <li>s at all. The only thing I had to do in my inbound $html was str_replace('</ul>', '</ul><br />', $html); to provide an extra line after the last <li> before the next paragraph. It's not perfect, but very close.
Which line in HTML2WordML.inc would I need to modify to allow it to read inline styles for the <ul> itself? Something like <ul style="margin-bottom:1em">. Is that possible? If this can be done, I think it -would- be perfect.
Thanks again.