This is a posting I submitted to the Association of Pole Turners ask and answer forum. I was fairly well received and nearly put an end to a three page thread.
You cannot measure efficiency in a vacuum. Neither can efficiency be optimized in a vacuum. Every thing in motion is both efficient and inefficient to a degree. If a thing is done as a hobby, efficiency is not as important as it is when a profit is expected and necessary to continuing the operation. With regard to pole turning, a broader knowledge of related woodworking craft is necessary as well as an understanding of the principles of design of the lathe such as having the center line of the work at the height of the turner‘s elbow which might call for a frame with height adjustments. It may be all well and good to measure wood chips per calorie burnt and to provide those who have a pedestrian interest in pole turning with properly functioning gear to take for a spin, but ultimately, those who are truly interested in becoming pole turners need to be exposed to a wide enough range of related arts and practices in order to produce not only their own gear but also to custom make the gear and to modify and adjust it to optimize their efforts. For instance, which tools are most effective for the intended purpose and how do you sharpen and apply them. Again, what sort of joinery is best suited for building a pole lathe for spindle work as opposed to bowl and plated turning and where best do you position the pole support in order to have enough flexibility that it is not too difficult to treadle without knocking one off balance or wear one out and still be able to return to the first position in a timely fashion for the next cut. A shave horse of some sort and perhaps a splitting/chopping block will have to be fashioned to prepare stock before it even gets to the lathe. How does one keep the cord for binding itself and preventing the return movement. . . In the end, the efficiency of a pole lathe, or any human powered machine, is almost entirely subjective and ultimately is an ever changing and hopefully improving experience rather than a measurable or fixed value