A few years ago David Knight gave me some caramelized Tonkin shafts at the Classic. Some had slight bends in them but when I tried to straighten them a few broke at a node. The shafts themselves are sound and tough but straightening an already reduced node, for me at least, will break 50% of the time or greater.
I straighten and temper hill cane before I ever reduce the node and usually I will heat and roll the nodes to reduce them.