I'm no Langdon or GJM, nor an M class shooter so take this for what it's worth. I am a LEM/Striker guy and have been working hard with a VP9 for almost a year now straight, (on and off before) but having recently been playing with the PX4 compact every day for the last few weeks the biggest and most helpful info I found was in Langdon's video. I believe it is the one you posted. Once you start the process of pulling the trigger don't stop. It pays to be aggressive with the trigger on the first shot working a press out or micro press as GJM said. Side note, I love this about the LEM and TDA guns. Once I stopped treating TDA/LEM guns like a two stage trigger my accuracy at speed improved across everything I shoot. The most baffling part is I now seem to be more accurate on the first shot with a DA pull than anything else. I am at the point now where I want to hate DA/SA and just stick with what I have been using but damn they are fun to shoot, you really get the best of both worlds. Good luck prepping for nationals, I wish you the best and I hope you kick some ass.