• Properties: more than just display,visibility
• Properties: XML-type animations (attributeType="XML") converted to CSS-type
• Attributes: calcMode,fill,keySplines,min,max,repeatDur,restart
• Elements: <animateColor>,<animateTransform>,<set>
• Time values: offset-syncbase
• CSS animation steps() for certain situations
• swap cheerio and css for jsdom (or domino) and jquery to support more advanced CSS styles
• …and some seemingly impossible features:
  • <animateMotion>,<mpath> elements
  • additive,accumulate,by attributes
  • Unmatching begin,repeatCount attribute values among sibling animation elements

CSS motion paths are now possible with https://www.chromestatus.com/feature/6190642178818048