will break the deletion code in the doSave() function on the base OM.
In doSave(), the ::create()->filterByPrimaryKeys($obj->getPrimaryKeys(false))->delete($con)
will not work, because one of the primary key field will be null.
I do not see any harm in removing this code. Tried it and did not see any problems.
Obviously, I have a composite primary key and part of this primary key is a foreign key from another table.