That still does not explain how some developers manage to make add-ons with 4K textures meanwhile others refuse even to look at them no matter how big or small they add-ons are.
Also, I am sorry if I again missing your point but wouldn’t a downsized texture look even better?
The same as with the 4K videos that would look way more better on 1080p monitor rather than 4K.
From what I remember the textures start to get blurry when you get a very small texture and stretch them instead.