I was in Macau a few months ago. I tried to do this, but at the time, the tower was closed. The tower is damn big, so I cannot imagine what it must be like jumping... backwards. This dude seems to handle it pretty well, but doing it backwards must definitely add a completely awesome new dimension!
If you are ever in China, I highly recommend doing this. The tower itself gives you an amazing view of Macau and all its hotels. Imagine that view as you go down haha