It's an interesting setup, and I like the fact it's an upright style as that matches my prefered riding position. There are some folks I've seen--GizmoDuck and Unisk8er specifically--that prefer a much lower position. Possibly the lower position offers less wind resistance, but it isn't a position I'm able to hold for long stretches of time.
But to your question on whether the bar would make UPDs too dangerous, I doubt it would be a factor. The main danger those boys face from a UPD is a head injury from their lack of helmets. Hopefully there's a law against it in Nova Scotia, so they can be protected from their folly.
