I asked because a basic pistol course I took through a different trainer was teaching just that to basic students. Like student who take 20 seconds to do a mag change students.
Manipulating the trigger while extending the gun to the target is a totally legitimate technique for certain uses, for certain shooters. For example, it can help if you have to deal with a long DA / DAO trigger pull, in terms of prepping the trigger during extension to save time. How much time it might save is anyone's guess, and I'm sure it's a debatable point. That being said, it's certainly not a technique I would ever want to teach to an inexperienced shooter, as there is serious potential for negligence and safety issues with those that do not already have excellent trigger control fundamentals.