Why dedoming improve throw by large margin, and why is the tint shift, are explained here .
Actually to be frank, I used to understand the dedoming mechanism as what you do now, but I think Dr. Jones explanation makes more sense. On a side note it is very difficult to find some recognized sources or journals which directly explain on the dedoming effect of the LED. Well, who else on earth except flashaholics like us would attempt to dedome a LED? It takes someone who has deep knowledge in every other aspect of optics to interpret the dedome mechanism.