I have noticed that you can not set cascade on key-many-to-one properties within a class. Is there any reason for this, or is there a plan to add this feature?

It does seem like a rare case that this would be necessary since hopefully the object which has key-many-to-one would be a child of the type within the key-many-to-one which is already cascaded from another direction. It still seems possible to create object graphs which would not result all objects becoming transient.