Funny that you post this thread....coinkydink.
Watched a YT video last week where a "tactical" dude was showing how to double-tap shots with a Glock. I am the least "tactical" sort of shooter, but while at the range last weekend I had to give this a go.
Did exactly what you and the YT guy said do....low and behold I double tapped a target. It was only like 15' away, but I did it. The wife even freeked when she saw it. She said "That almost sounded/looked like one shot, but you put two in the target.
(tried it again, but I missed the seconcd shot)
I can see how this could be practiced for refinement after time.