My concern is that the bark damage and poor circulation may ultimately kill the tree. Also, the narrow aspects of the tree that contains the damage would be a weak point in the tree, that will further weaken by being shaken to obtain the fruit which will cause the tree to fail at the weak point. In using the device, I would place the device on the tree without being too tight on the bark to cause damage during initial installment. The tree should grow into the device, and the areas above and below the device will have the opportunity to grow wider than the area in the device, resulting in the intended form. I would also consider putting the device on and off periodically. If you leave it on for too long the tree will grow over it, defeating the purpose. With periodic removal the tree may obtain minimal damage in the process of girdling. I think to test whether it will work as desired, the minimum experiement of 5 test trees to 2 controls is a good start to gauge success. From there I would continue to increase test subject and variables. Lastly, you may wish to enrich the soil nutrients (elements) since the tree will be stressed as well as water regularly. Please keep me updated on how it goes :)
Answer: our last experiment showed no bark damage or other issues.