Materials/textures, collections, and rendering in Cycles

I’ve noticed that if I have a very large scene, split up into collections, it seems that the textures from the objects of disabled collections are still loaded into VRAM/RAM for the final render. So if I have 4GB of textures, and I disable every single collection in my scene, I still see 4GB get loaded into RAM for the render, even though those textures are used nowhere. Is my assessment of this behavior correct, and if so, is there a workaround?