enki,
I don't think you have any serious experience of Yoga or Pranayama or meditations.
Not just in Hinduism but also in Jain and Buddhist traditions, spiritual aspirants can be guided in very specific ways to achieve very specific goals. Sometimes on a one to one basis, they can even be guided thought by thought, emotion by emotion to achieve certain mental states.
There are rarely any wide range of interpretations.....only different paths and different stages of development. Different paths and different milestones are fairly clearly understood by Yogis and other teachers.