Scaling down the exclusive children screenshot.
Patching up the sorting layer functionality to use IDs exclusively and to fix the assumption that IDs match indices.
Sorting layer IDs are based on the order in which layers are created and do not change even if layers are renamed, reordered, or removed. There's another utility method we can use to convert between an index into the array of the sorting layers and the IDs themselves, so we don't have to worry. This solution is likely much closer to how the SpriteRenderer is implemented.