Can the TwinDolly and TrussDolly run upside down?

Whereas the TwinDolly is principally built to be used upside up, the TrussDolly is in the first placeĀ builtĀ to be used upside down.
The TwinDolly can be used upside down when you use the bowl risers to get the bowl underneath the dolly in between the TwinTube (as per picture in link
The TrussDolly can be used either way although it does need more rigging support using upside up.