I think it might work out if it worked more like the Deku Leaf in Wind Waker. Something to break a fall or glide to other locations if Link is in too many high up places. Falling is still a huge hazard in a Zelda game and some special item to help survive it would be incredibly useful, especially since there cannot always be a cuccoo around. and the hookshot/clawshot is only useful from a standing location not when falling. I could also see it working like the hover boots, and Link would just glide over a hole or cliff to the other side easily. Then there would be no need for a jump ability to be added, just run off the ledge with the cape equipped.
For people living in the air like Skyloft one would think they have some special means to protect themselves from falling. Or safe travel around the island,I imagine this is why there was a clawshot in the City in the Sky in TP. It is necessary to get around in the area for story purposes, not just as a dungeon gimmick. Also for a storytelling point, it makes sense for a people that live in the sky to actually take the time out to collect Roc's feathers and make the capes for use.