There should be a way for custom OptiFine capes... | Hypixel Forums
optifine cape | Nova Skin
A few Elytra textures for capes... but don't fret! I've researched the hurdles to make the textures customizable as skins, and it will be added eventually (unknown ETA) : r/Minecraft
Let's get this sub started with my skin and Optifine cape/elytra. : r/gayminecraft
Suggestion] OptiFine Cape Donators should be able to have Elytra skins too · Issue #1848 · sp614x/optifine · GitHub