When drawing a foreign key from parent to child, the parent primary key is used.
If I then change the parent key to an alternate key instead of the primary key, new columns are created in the child entity, EVEN WHEN columns of the same name already exist.
To make matters worse, there seems to be a column remapping bug whereby the first attempt at remapping never works, and it has to be done again. It works the second time.
Is there any way to make column mapping use existing columns when changing the parent to an alternate key?