Do you know the testure pack ItemBound from Sixfootblue? If you don't what he has done is that he made use of a fewture that optifine has to change the textures of the items by renaming them for example you take a diamod sword and you rename it Diamond Katana and it changes in a diamond katana. You have done the same thing with your elytra if you rename an elytra from Elytra1 to Elytra20 you have all your textures without the use of the command block and you don't need to be op. I like your elytras so if you can add an icon for them to i will definetly use this resource pack. Also take a diamond for the nice elytras.

Cool