the sticks are black, so hiding them in a colored fabric sleeve isn't very visually appealing, it's still a shadow or dark line thru the graphics.
The purpose of this sleeve is to protect the sail, then mount the protection ONTO the sail and don't mess with the frame members at all.
This is a solution, but not in the direction I would travel.
By the time the sail fabric has cracked, the rest of the kite is beat-up as well. Why bother?, this is not going to extend the life by two years!
Reinforcing patches at the leading edge, now that is good use of materials, labor and weight and it will make a difference in life-span on your kite too