I figured it out. I added the following code to generatePPr() around line 1592 (for some reason, my file line numbers are slightly different that yours..)
else{
$stringPPr .= $this->pPrSpacing($properties);
}
It works, and I have not noticed any ill effects. Now <ul>s and <ol>s are rendered perfectly, even with strictWordStyles = true.
Thanks for the help.