Do jing and shen polarize in Early Heaven?​

I’ve been trying to get my head around Daoist cosmology and am (more than) a little confused.

As I understand it, at a very general level, the cosmological story is that from a potent nothingness/emptiness (“wuji”) comes a unified something/unity, which then becomes multiple somethings/a multiplicity (“the ten thousand things”).

One of the things that I’m confused about is the story at the point where the unity begins to become a multiplicity.

In his Daoist Internal Alchemy paper, Michael describes this unity as a cosmic egg within which yuan jing, yuan qi and yuan shen exist as one i.e. the “original trinity-in-one”. Michael also says that, within this cosmic egg, three potential forces – yin, yuan and yang – exist as one.

When the cosmic egg cracks open and multiplicity begins – the start of so-called “Early Heaven” – Michael says that jing, qi and shen separate. He further says that the three forces – yin, yuan and yang – come into being and act up the qi (which has separated from the jing and shen) in such a way that 25% becomes yin qi, 25% becomes yang qi and 50% remains as yuan qi.

However, Michael doesn’t appear to say anything in the paper about whether the three forces act upon jing and shen in the same way i.e. do we also get (A) 25% yin jing, 25% yang jing and 50% yang jing and(B) 25% yin shen, 25% yang shen and 50% yuan shen?

If so, can someone say a little more about this? And if not, why it is that qi polarizes into yin and yang but not jing or shen?