Here's one more link to share: the Atom Z2760 datasheet. Page 12 has a diagram for an example system that specifically mentions providing HDMI and line out to a dock. However, I don't think checking continuity from the dock connector to the external jacks will work, as the diagram indicates a demux on the HDMI line and possibly an amplifier on the headphone jack vs. line out. So, not sure how to tell if Asus kindly included those items on the dock connector without opening the case and poking around. Probably not worth the risk.