When I was a kid in Boy Scouts and we were doing some leather tooling, you soak the leather in cold water for maybe five minutes so that the leather could absorb the water and become quite pliant. Then when you tooled it (stamping various shaped dies with a mallet) the leather would retain that shape after it was dried.
So, yeah, the article you referenced that said hot water for five minutes and maybe another five minutes if you still thought it was stiff, that was pretty much equivalent to a soak in cold water that we did to make the leather pliable for tooling. And pretty similar to soaking in rainwater for a few hours.
But I suppose the tooled leather tool holders on one of my work belts that I made decades ago and used to use before I retired is a figment of my imagination.
I have used a Brooks that was broken in, probably as described as that article you cited. In the 70s I bought a used bike, had a Brooks Pro with a 1962 date code, it was as soft as glove leather. Very comfortable for a 20 mile ride, but at century distance was not so comfortable for me. That said, some people like soft saddles and would probably love it, others would hate it more than I did. I still have that vingtage Brooks on a shelf somewhere, but it came off that bike in the 1980s when I could afford a replacement.
There are people that like soft saddles, a friend of mine used this one on a tour. And he liked it. But I thought he was nuts.
That said, if he liked it, it was his butt and not mine so I did not argue with him about his saddle.
Maybe that soak method works for you, and if so great. Glad you like it.