I recently took the tactical pistol course from Ernest Langdon and he did touch briefly on the DA/SA but not too intensely and I’m guessing it was because he wanted to cater his training to everyone including the non-DA/SA shooters. That being said I recently switched to DA/SA in January and I found you can learn a lot from just googling and YouTubing pointers and lessons on how to master the DA/SA. Dry-firing will help a lot too. That should at least get you started until you find class that can help with your specific needs.