Just a comment... shotgun triggers generally should be pulled hard, "Crushed" is my favorite term, straight back and with authority. If pulled hard enough your finger should stay on the trigger, with the trigger back, until the gun comes out of recoil.
Put the trigger blade behind the first joint from your fingertip. Pull like you mean it.... hold it there while following through with the shot, head down, tracking flight path, etc...
There will be plenty of time to switch to the second trigger after the first shot is finished..
