$ mvn -o -B test -Dtest=SortingTest#criteriaOrder_acrossAJoin
(trimmed to the test's own RESULT line)

RESULT[sorting-criteria-order-join]: Criteria root.join("playlist") ordered by the JOINED entity's name -- [A-Playlist, B-Playlist] -- proves Order in the Criteria API is not limited to the root entity's own columns.