I'm using some free placeholder assets for my project, but some of them are in sprite sheets. I've seen that Texture Atlas is far more efficient than having individual textures for each item. However, all the examples for using the Texture Atlas is for animations. For my situation, I've got a large selection of item icons, some with different sizes. I noticed that the auto slice will correctly encapsulate the individual sprites, but that's seemingly only for editor ui convenience.
Is there something similar to how Tilesets work, but for textures? Being able to mark out and make individual sprites with names and unique IDs is what I'm after.