The Core ML developer guide recommends saving reusable compiled Core ML models to a permanent location to avoid unnecessary rebuilds when creating a Core ML model instance.
However, there is no location that remains consistent across app updates, since each update changes the UUID associated with the app’s resources path
/var/mobile/Containers/Data/Application/<UUID>/Library/Application Support/
As a result, Core ML rebuilds models even if they are unchanged and located in the same relative directory within the app’s file structure.