Hmm. Well, the back-and-forth comments aside, I am still wondering how the methods work.
They have been described as balancing post-heaven in order to cultivate pre-heaven energy/resources. I thought that was what most forms of qigong/neigong had done. With the Taoist Yoga, we balance the post-heaven energy with the quick-fire methods that are meant to refine generative force by circulating it in the microcosmic orbit. There are a prescribed number of rotations that seem to have celestial significance.
Balance is the balance of Yin and Yang.
By the method you described, you can get an excess of Yang by means of exhausting the "generative force" Jing.
Such method is dangerous and have no relation to the alchemist "quick fire".
Daogong uses more gentle, natural approach, similar to Zhang Zhuan.
Granted, this will fill and stabilize the physical and post-heavenly level of functioning and does not constitute full transmutation. But, after this is established, there is also the selectively reversed cycling so as to purify with the slow fires. It is described as raising positive fire and lowering negative fire (these were generated during the microcosmic orbiting) and it works to further refine the post-heavenly so as to approach the pre-heavenly.
Taoist Yoga and Zhao Bichen tried to express so called "northern method" with some Buddhist additions. In Wu-Liu Pai such method is known, but the major way is so called "southern method " which has no relation to what you describe.
Now, I am slightly confused. It was described (by you) that Taoist Yoga will will burn pre-heavenly to preserve post-heavenly. I don't quite see how it burns pre-heavenly. Not unless the pre-heavenly is somehow engaged when "the light is turned around" and the gaze is inward. Then again, since this is done so that the faculty of the third eye can be used to move and refine the body's resources, I don't know what resources it might require in order to do what it does.
Any postheaven work needs preheaven to be spent. So if you want more postheaven work, you burn more preheaven. Like fuel.
But, all of this aside, if the alchemical methods of the Wuliu Pai are unique and unlike any of the other schools out there, how is the direct pre-heavenly cultivation engaged? Just going from the Taoist Yoga works (and the topical explanation that I had read), it doesn't seem like it is that different.
This is the main secret of the southern, ancient method of the alchemy: those who know it progress fast and relatively easy, while the method partially described in Taoist Yoga is considered to be slow and hard.
There are no public texts about the ancient method, so basically there is nothing to compare.
Northern method is not unique and known in many various schools. So probably you read some texts about it and they have evident similarity with Zhao Bichen.