Could you explain the ramifications of Wei Qi activating the diaphragm at the deep levels (presumably at night) cant be just to keep breathing as it is an autonomous action day and night, is it to expel EFP’s by way of the lungs? Is it the night time ‘guard’ there so to speak while all is asleep and liver and wei Qi are being stored ready for the morning activation to surface?
Wei Qi is a defensive energy. It prevents EPFs to go in (to expel an EPF we need all the ensemble of Qi – Zheng Qi – at our disposal ). Note that the character Wei has to do with the leather shields were made of. Wei Qi works by activating energetically/functionally the structural/material layer protecting the body: MUSCLES. Muscles envelop, protect the interior too hence Wei Qi moves to the interior/yin too. When? At Yin time.
This is a way to explain how the function/Qi relates to the structure/Muscles. Please note that Wei Qi circulates in the TMM which function is to move the muscles.
Wei Qi is physiological, it always there even in absence of pathogenic factors.
The comments in your CM notes about the excess Wei Qi being stored in the Liv should not be taken literally. What is the Liv/Gan in CM? Not just the physical organ as defined in WM but rather all its ramifications throughout the body (in functional and structural sense): muscles and tendons being one of them.
Finally you can read about the relationship between Wei Qi and Diaphragm in the “survey of TCM” by Larre et al: “the wei Qi warms the diaphragm”
At full moon I think we get stronger tides as the moon pulls the sea up maybe wei Qi on its monthly cycle is pulled up in the same way (Lunatic at full moon) which would explain it not being so high at the crescent stage, I dont understand where the attach of ‘ summer heat’ comes in, perhaps it is the fullness of Yang?
The Su Wen is not clear about the circulation of Wei Qi according to the moon. This circulation is described in case of an attack of Summer Heat (Malaria) so we do not know if Wei Qi circulates along that trajectory every month or if it only happens in case of an attack of Summer Heat.