indeed, it probably does, since almost all small boats have them, and many vastly outpoint kiteboards.dagger board must really work well to get the kiter upwind
The thing that matters most to windward is the angle, and a dagger takes you higher, also it's a high AR foil with (theoretically) less drag for the required lift than the super-low AR foil of the board edge.
Going downwind, the advantage would be that you get rid of all the drag of the dagger, and have only little fins for tracking....
Will it win? Dunno but looks worth trying....