On "Representative node" relationship "Representative sort order" doesn't work

How to replicate the problem:

• Create a View (Term)
• Choose the vocabulary
• Continue to edit the View
• Add the relationship "taxonomy Term: Representative node"

now choosing any "Representative sort criteria" and "Representative sort order" the sort order has no effect. Indeed the Preview SQL query has no "ORDER" clause.

Also the 7.x-3.x-dev seems affected.

Am I doing something wrong?

UPDATE:
Debugging the query using hook_views_query_alter() I noticed that the left_query ($query->table_queue['node_taxonomy_term_data']['join']->left_query) is using (some) default settings. The ORDER BY clause is always:
ORDER BY nodeINNER.nid ASC