Textures placed in the following directories don't get injected into programmer art:
"programmer_art/assets/minecraft/textures/item",
"programmer_art/assets/minecraft/textures/entity",
"programmer_art/assets/minecraft/textures/mob_effect",
"programmer_art/assets/minecraft/textures/gui"
But these ones do:
"programmer_art/assets/minecraft/textures/block",
"programmer_art/assets/minecraft/textures/font",
"programmer_art/assets/minecraft/textures/particle"