I find this story incredibly sad. It was my experience, when I began to research and learn, that the dive shop where I had gotten certified, where everyone had been so nice and so supportive, suddenly became judgmental and negative. It was a huge letdown. It got worse as I learned more.
One of the tragedies of diving is that so many people who run shops and teach know so little. Worse, they are so often wedded to the little they know and the way they have "always done it", that they are unwilling to learn, grow, or change.
In my profession, continuing education is mandated, both for one's medicolegal safety, and because the State requires it. In diving, there is no requirement for any continuing education -- if you became an instructor in 1962, you are good to go forever, regardless of how the approach to teaching diving evolves. For example, in our own shop, we have a group of instructors. PADI published an article on early transition to neutral buoyancy in their agency magazine about 2 years ago, and changed the standard for the open water class to reflect the content of that article as of the beginning of 2014. But in our shop, almost all the instructors teach the way they were taught, despite the change in emphasis and curriculum that the agency itself has promulgated.
To the OP -- I am glad you are thinking. I do not use a pony bottle myself, because I have chosen another approach to reliable redundancy. But if this is the route you wish to take, TAKE IT. If your shop can't wrap its head around a redundant air source, find someplace that can. As you say, you are in a region with a lot of advanced diving and advanced instruction. There is no reason to remain in the stone age . . . find someone who can teach a thinking diver, and continue to soak up information and make informed decisions.
