I'd like to apologize beforehand if this question has been covered in previous threads already. I was almost certain that it had but a search or two didn't generate anything that I thought matched.
I'm still a beginner at meditation so my question might not be the most sophisticated conceptually but here it goes:
Even though I've read fairly widely in the last few years I've been a follower of Thanissaro Bhikkhu's writings and talks for some time now because of his eloquence in expounding a very logical dhamma framework. I've especially taken an interest in the way he frames the meditation experience and the employment of 'fabrication' (sankhara) in order to further concentration and deepening states of samadhi. I don't have a quote handy at the moment but can find one later if pressed, but basically he says (and please correct me if you think my understanding of this is flawed) that the process of focusing your attention and perceiving the breath in the body is a fabrication in itself because it is still fashioned from the preceding stages in dependent co-arising which would thus make un-conditioned perception impossible. However, the process of fabricating these experiences in the right way works as an aid in focusing one's concentration. This makes very much sense to me.
With this explanation fresh in mind I attended a Goenka retreat a few days ago and was introduced to this particular movement's take on vedana and sankharas which brings me to my question:
Goenka talks about how after three days of his Anapana instructions absolute beginners to meditation can start experiencing the kalapas as subatomic particles arising and passing away on the surface of the skin and how this is the continuing arising and passing away of the whole bodily structure. This sounds relatively incredulous to me if it's intended to be taken literally. In his daily discourses Goenka is often heard talking about perceiving reality "as it is, not as you would like it to be" and observing the truth about the kalapas. It however sounds highly unlikely to me that anyone would think of these subtle bodily sensations as kalapas arising and passing unless one was given this framework of perception to begin with.
To my mind the act of focusing on a certain area of the body and/or perceiving it as myriads of kalapas an act of using perception and sankhara (in the case of shaping your experience) right there but no indication of this is given. At one time when I consulted the assistant teacher present about using the breath to focus on vedana he answered approvingly about using the breathing to pace the scanning but when I immediately after said that I like to use a perception of the breath opening up the whole body to experience the sensations more throughly he said "No, that's imagining things. We don't do that."
My thinking was at first that this is an instruction to so-called new students and that this experience of vedana is an aid to the practice and subsequent progress within the tradition will expound more on the relationship of this view of the body/perception. But I guess this is my question: is this role of using perception acknowledged in the Goenka tradition or do they speak of this 'objective reality' all the way thru? And how about other traditions that I'm less familiar with?