Nope. not that I know of, I dont think the Iburst service can actualy be changed by resellers. So what Iburst says on their site goes I assume.
You can always just use the old Openweb or nukecap proxies to get past whatever problem youre facing, assuming its just one or two apps that you need unshaped.
Most WISP are unshaped except for P2P and VOIP, but not Iburst. They act more like Telkom DSL on their shaping, but they shape everything to gaurenteed 64kb, at least you know what youre gonna get.