@Stevie Boy Good questions... an edge change doesn't happen unless you allow it to happen. If I need to pull all the way to the next buoy to get that extra 1/4 buoy, then my edge change is not going to come until much later. You have to learn to separate what is happening with the ski and whether it is on the accelerating or gliding edge, and whether or not the upper body is leaning away from the boat keeping tension on the line or getting ready to commit to leaning inside to make a turn.
In general, the ski should be on the accelerating edge up to the center line of the boat guides. If you continue to accelerate much past the center of the course then you are going to be carrying more speed into the buoy.
Lean away from the boat and into the desired direction of travel should be intense. Nate makes it look easy, but he is putting in effort.
Don't think of it as an edge "change", think of it as the moment that you are done accelerating and you need to go into a glide. You've built up the energy and the speed out of the buoy, and now you need to allow that energy to carry you or swing you out wider than the next buoy.
The idea of edge "change" gets skiers allowing their upper bodies to go from a lean away from the boat to a lean back into the boat way too quickly. The goal is to stop the acceleration, but manage to keep some away tension on the rope as you swing out to the next buoy. You want to decrease your lean away from the boat, but not totally eliminate it.
The reason you feel differently on the gates is that you are not approaching the center line of the course with as much energy as you are when you are coming out of a buoy. Build more energy on your approach for the gates. The gates set the rhythm for the rest of the pass, so try to establish the rhythm that you would like to use throughout the entire course.
Give it a try, and see if that makes any difference.