Found a new strategy on the bend in the canyon by going through the archway and hitting the wall behind the center pillar. The reason why this is faster is because it allows for more momentum going into that giant desert stretch.
The only major time skip I know of that may only ever be possible in a TAS is bouncing off of one of the trees between checkpoints 4 and 5 to instantly turn the corner. I did it once accidentally in a run. Nothing came of it, but it was easily the fastest method. It was one of the trees under the rock ledge, and it resembled the wall bounce I found between checkpoints 1 and 2.
I have no idea how someone would recreate this, but it definitely is possible.
There are still a few things in this level that haven't been taken advantage of, but they require high serendipity.
