Its hard to find much review on the approach after having a short look around myself, and I won't comment because I'm not at all familiar with it.
However, I would suggest that you may like to check out the taubman approach, which you can find out about at
www.golandskyinstitute.org - its initial/primary point of learning is rotation.
There are plenty of raving reviews, and plenty of enormously skeptical ones that point out many potential problems.
Barbara listersink also has an injury preventative method where the primary motion is rotation I believe, I haven't read her book, but if you'd like to its called "freeing the caged bird".
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In all cases, it is also dependent on the quality of the individual teacher, and how well they know the material and how to apply it both as a pianist and a teacher. Your teacher may have learnt from a WPP teacher, who learnt from some other WPP teacher and ultimately be a very far cry from N. Jane Tan both in ability to teach the skills and even actually having them to an advanced level. However, its probably also too soon for you to tell with your limited experience.
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You should also be enormously skeptical of a method that tells you anything like all other approaches are wrong, or doesn't allow room for exploration of other ideas. And, one that focuses for an extended period on a physical movement without reference to a sound you are trying to produce comfortably. After all, the point is to sound good as well as feel "relaxed" (its not actually done by relaxing by the way, that's the wrong word. Think about it. Its consciously moving in a comfortable way).
You should take your information from a multitude of sources and be your own judge of what works and what doesn't.
8-10 lessons is nothing by the way. It can take decades of guidance to refine a piano technique.