New divers are routinely trained successfully in BP&W's.
1. If you're saying that the majority of new divers are being trained with BP/Ws, you obviously have no idea what's really going on in the dive industry.
2. Who do you think trains the majority of the divers? Answer: It's Instructors who teach through or for the LDS!
3. You state that: "Given that BP&W's aren't widely stocked, and few LDS know anything about them..."
Given that the LDS Instructors train more divers, how can the divers be "routinely trained successfully in BP&W's?"
Who's routinely teaching with BP/Ws??? From your personal experience, how many divers are trained yearly by the groups you are aware of? I'm happy to contact them and confirm this information.
I'm not saying that this doesn't happen, but it is by far the vast minority of OW divers trained. In my experience, I have no personal knowledge of any instructor teaching OW in BP/Ws other than groups who's mission is underwater exploration. I'm also not ruling out similar groups in the scientific diving population and some individual instructors, but again no where near a significant number.
You may prefer to paint a different picture, but the FACTS remain unchanged.
The facts are: that Aqualung/ U.S. Divers, Seaquest, Mares, Dacor, Cressi, Tusa, Scubapro and Zeagle are the big names in the diver flotation business. The majority of BCs sold worldwide are NOT BP/Ws. Obviously Deep Sea Supply (your pocket-book) would like for things to be different, but no matter how much YOU would like to paint a different picture. the FACTS remain unchanged.
I maintain that "A new diver is better able (safer) to use equipment that is similar to the equipment that s/he has trained on. The diver needs to first gain a degree of experience until a transition may be made that will maximize safety."
I would agree that should a BP/W be used in training, the diver should be encouraged to use this equipment after s/he's certified. As the majority are trained with Jacket BCs....
Perhaps you would like to address this point...