As I said I arrived to Qigong practicing WH. I found that many Hoffers use Qigong with the breathing method of Wim (often as a warming training), so due to pandemic I looked for something that could be practiced online and with few space since at home I cannot move to much (otherwise I would have chosen taichi). I followed some videos of Lee Holden. I simply followed the movements and found that after it the breathing rounds are more easy, probably because they relax the body and open better the diaphragm, but it's only my supposition.
I found that he suggest the same breathing pattern of Wim starting from the belly (in qigong it's called tantien) and finishing to the head, so it seams to me that there are similarities between them.
It's interesting your discussion about the contrast between qigong and WH due to the use of kidneys. Honestly, since I'm a practical person and considering that it's not measurable the energy (or QI) I like to practice and decide accordingly to the results, and I found that WH is useful to lower the stress. Consider that the Wh Method is often misunderstood, mainly from people that start only with the youtube videos. The heat generation for example happens if you increase the speed of breathing hyperventilating, but it's not the only way to practice. Obviously is useful to generate heat before immersing on cold water.
About the kidneys consumption I cannot understand in which way they could be damaged, and due to few studies in the long term of the method I doubt there is some evidences about it.
Anyway if you still can suggest me an online Qigong course I'll apreciate.