Empty slot textures

Hi. I'm making a resource pack for Minecraft Java and I stumbled upon one particular problem.
My idea is to make custom GUI textures for every block, but since Inventory, Enchanting table and Smithing Table use the same empty slot textures, I cannot do exactly what I want.
So my suggestion is to make separate textures for Inventory, Enchanting table and Smithing table empty slots, so people who make resource packs could make different textures depending on a block they're making the textures for.