I myself was thinking of a few ways the hoverboard could be improved:

1) It could give you extra height when flying off an upward slope.
2) It could have a chance to turn non-perfect landings into perfect landings (or provide even more speed when you get perfect landings). This could stack with items that provide similar effects.
3) The acceleration could increase with how long you keep the button held.
4) Its energy consumption could be decreased.