"And what is just the craziest thing about this is that singing is an activity strongly characterised by sensation and having certain experiences while singing, and you're here arguing about how a particular sensation/experience is wrongly experienced by people who experience it (effortless natural vibrato)"

1. where did I see singers' experiences are "wrong"? Wrongly? Wrong? No. I'm here arguing that it can be developed and learned. My first source proves it. That doesn't discount anyone's experience.
   " If there comes a day you achieve natural vibrato you'll be ashamed of this post and what you're trying to argue in the comments "
   .
   Your definition of "natural vibrato" and mine is different. Regardless, I'd never look back and be ashamed of a post if my views ever changed. Instead, I'd laugh about how I had the balls to explore possibilities and not give a sh** about what people thought, even if it was unconventional. I'll be able to tell myself I did my best to be objective with the limited resources of knowledge I had at my disposal (the studies in OP).