Ken, nowhere in the link you gave does it address moving a bare-rooted, tap-rooted tree; it isn't talking about transplanting an established tree, but deals with planting commercially grown trees, either potted or bare root, which are regularly root pruned. It really doesn't pertain to Bart's situation at all. It also contains at least two special rules for certain trees, one for evergreens, and one for fleshy-rooted trees :D

A tree with a deep tap root, and few feeder roots, WILL die if the majority of the tap root isn't preserved. This mostly applies to younger trees, as *eventually* all tap-rooted trees will develop side roots. In some, the tap root eventually even completely withers (oaks, for instance). But Bart's tree is only six years old. Its main root may still be the tap root. Nut trees, aesculus, oaks, redbuds, and paulownia are just some of the trees you have to be careful with as young trees. Up to a certain age, the tap root is the ONLY root, with many peripheral hairlike feeder roots growing directly from the tap root. The black cherry you show is not necessarily a tap-rooted tree. It grows a shallow, wide spreading system almost from the start, in addition to an anchor root, like most of the prunus group.

Bart, I would suggest you gently dig around the base of your tree and see if you can find any indication of strong, horizontally oriented feeder roots. If they are there, your chances of successfully moving your Princess tree are much enhanced.