Long story short is that you want to let them get about an inch or two above the net and then move them to the next hole over, let them grow another inch or two until they can reach the next hole over, etc. The idea with scrogging is that you are using it to spread all of the peripheral branches away from the main cola, but to do that they need to be talked into growing, which you do by bending the main cola and getting the growth hormone to go to lower branches. Hope that answers your question.
ps. glad that video helped!
To be honest when the net was lower watering was a major pain in the ass but I ended up finding a really cool watering can that is quite short with a long spout that can hold a liter so I mix my solution up in a gallon jug and then transfer about a half liter at a time to the watering can and water each plant with that. As far as not moving it that's actually a benefit in my mind because the less you move them the less chance something could go wrong(drop, crush, dog, etc.)