It should have two harps, because of some of the chords that have more than eight notes, but also at G in the second movement, where it is much better to split between two harpists. Also, in the third movement at H, the second harpist can play the bass octaves while the first harpist takes the chords. Since the chords are so wide, it would make sense for the second harpist to play the bottom section of the chords with the right hand while playing the octaves with the left. This is an exposed section. At 4 before K, and K, the harp parts can be split between the two players. I wrote out this section to avoid the page turn. (Attached.)