I think the problem/reason is in org.hibernate.envers.entities.mapper.relation.lazy.ToOneDelegateSessionImplementor#doImmediateLoad

public Object doImmediateLoad(String entityName) throws HibernateException {
    if(entCfg.getNotVersionEntityConfiguration(entityName) == null){
        // audited relation, look up entity with envers
        return versionsReader.find(entityClass, entityName, entityId, revision);
    } else {
        // notAudited relation, look up entity with hibernate
        return delegate.immediateLoad(entityName, (Serializable) entityId);
    }
}

The versionsReader.find(...) is used always to return result immediatly if entityName is configured as @Audited,
doesn't matter if it is only asking reference for property annotated as targetAuditMode=RelationTargetAuditMode.NOT_AUDITED (Employee.company from example in description)

What about to slightly change ToOneDelegateSessionImplementor#doImmediateLoad
and add fallback to delegate if versionsReader.find(entityClass, entityName, entityId, revision) == null ?

public Object doImmediateLoad(String entityName) throws HibernateException {
    Object immediatlyLoaded = null;
    if (entCfg.getNotVersionEntityConfiguration(entityName) == null) {
        // audited relation, look up entity with envers
        immediatlyLoaded = versionsReader.find(entityClass, entityName, entityId, revision);		
    }
    if (immediatlyLoaded == null) {
        // notAudited relation or relation is not in AUD table, look up entity with hibernate
        return delegate.immediateLoad(entityName, (Serializable) entityId);	
    }
}

It doesn't solve problem mentioned in description with 'purging feature' but solves the real case
when we started with @Audited Employee but not-audited Company and after some period made Company @Audited

So it is easier than what proposed in description

1. Look up related entity with the max revision number equal or less than the targeted entity's revision number.
2. If not found, look up related entity with the min revision number larger than the targeted entity's revision number.
3. If not found, look up related entity in "current" version.
4. If not found, return null or empty entity with id field populated.

and just
1. Look up related entity with the max revision number equal or less than the targeted entity's revision number. // versionsReader.find(entityClass, entityName, entityId, revision);
2. If not found, look up related entity in "current" version in real table // delegate.immediateLoad(entityName, (Serializable) entityId);

Otherwise we have to create initial revisions for Company in scope of migration effort
Is there some generic tool to do this ?
I found

• https://community.jboss.org/thread/177321?tstart=0
• http://stackoverflow.com/questions/898529/populate-envers-revision-tables-with-existing-data-from-hibernate-entities
• https://github.com/hydra1983/hibernate-envers-tools