I think I might have a hunch as to what Hatori is doing.
The Buddha's palm is something Sun Wukong failed to escape from no matter how fast he went, because it encompasses all of existence. Similarly, reading the scroll caused Hatori to zoom up extremely fast, yet he could still not escape to anywhere.
Reading the scroll gave Hatori enlightenment, showing him the sunset and letting him realize that he is a part of 'Buddha's palm' – the wonderful world he inhabits. Now, what does the scroll's words do? It is translated as "earth transformation magic," but that doesn't entirely capture the nuance of the original kanji.
I suspect Hatori is levitating by moving "Buddha's palm," literally moving the universe relative to him, such that he appears to remain stationary while actually falling. He gets a view of the 'true realm' beyond Buddha's palm after attaining enlightenment, after all, and appreciates that his physical universe is not everything.