To your point about the difficulty of finding a good coach to train enunciation, you should look for a parallel track. A trite example is the scene from Pumping

To your point about the difficulty of finding a good coach to train enunciation, you should look for a parallel track. A trite example is the scene from Pumping Iron where Schwarzenegger takes ballet classes to help improve his posing. You want someone who can train you in an area that requires the same skills but for a different purpose. I would look to stage acting where the performer is required to speak clearly and forcefully enough that a large audience can understand what they are saying while still maintaining control over their voice. Maybe a Shakespearean acting coach could help you.