Since I have 'levels' on the brain presently...
You stated:
< The postures give you the theatre in which you can learn to practice using intent and to see how intent works> Audi.
I would say now, based on the theory that the nine levels represent 'teaching and learning' levels, that I can better comprehend what you are saying about <learning to practice using intent and to see how intent works>.
This could probably be considered level two (jing-chi, body-mind level)
...This would be <an appropriate theatre to practice using intent> (for future use of intent against an opponent?) and it would also be the appropriate time to <see how intent works>
But, I am not so sure that it applies to any higher levels than the initiating one...
Are you aware of the official existance of different 'levels' towards learning 'intention' in Taijiquan?
When do you think it is appropriate to introduce yi into a students curriculum?
The distinction of various levels of intention leads me to better appreciate the degree of difficulty in discussong such matters. If all aboard are on the same level of instruction, then it might be easier, but then again, maybe not.
Yi, I find, has easily been the most complex aspect of Taijiquan that I have thusfar encountered.
Not easy to convey in any manner and even more trying to understand.
Oh well...Onward

Thank-you,
Best regards,
Psalchemist.