Chakras as Transformers
I am reading Theories of the Chakras by Hiroshi Motoyama, and find it both interesting and clear (Ken Wilber seems to have used it as one of the main sources for his chapter of subtle energies in the upcoming book Kosmic Karma).
Our Being - from nondual through to physical matter - is a seamless whole, whether we see it as our human self or the whole world of phenomena (both possible). At the same time, we are free to add an overlay of abstraction to it and differentiate out various aspects.
One of the functions of chakras, as Motoyama describes it, is to transform/channel energy between the various layers of our being.
During my initial awakening, there was a tremendous amount of energy puring in - including to the physical/body level. There was a tremendous capacity for activity and engagement in the world, including very little need for sleep. It was pretty clear that the energy came from the awakening (F7-F9 and nondual), and Motoyama identifies one of the possible mechanisms for how this energy gets channeled and transformed through the system - including to the physical body.
In Wilber's framework, we can maybe say that the energy got channeled from F8 (subtle) and down through to F1 (physical body). There was little to resist it, as everything - all those levels - were brought more into awareness.