A check if model has anything to update

$allowedFields has only name, and name is not changed.
So There is no data to update.

You misunderstood me. I understand what and why happens. I'm looking for a solution.

1. Entity doesn't know about $allowedFields so its ::hasChanged() is unreliable for this case
   
2. Model doesn't have anything like ::hasChanged($entity)
   

It means that current there is no way to check if save() will have anything to update OR not (& will throw an exception).