You've got to be kidding... every platforming is scripted in LoS. The fact that you could do that is because they didn't scipt it properly. Try that anywhere else. There is one part where you fall down and can't jump back out because of an invisible wall, regardless if you can double jump or not. And almost every hand held requires you to go through the motions instead of skipping through with double jump.
If it were really not magnetic platforming like you say, then why isn't that half the time I can't jump a cross a chasm anywhere else except for where there is a spiderweb for me to "walk" over.
Just go to 1-3, after the troll fight. The whole platforming segment where you first use rappeling. You can mistime jumps, you will fall to your death if don't jump from the edge of the platform and so on.
Now pick up Enslaved or Uncharted. If you're not on a spot where the game registers the beginning of the jumping QTE, you will not even begin to jump. If you are on a spot where the jump is registered, you'll land on destination no matter what. The difference is massive.
I'm on Corneliab's page that not enough was done with the platforming sequences (the Necromancer's Abyss was expecially grating because it was the perfect place to play around and instead it was too conservative and saved you from failed jumps too often), but the system itself is perfect and refreshing in this age of magnetic platforming.