I haven't found a way to get the names of the failed test-cases via REST

When issuing a

.../robot/api/json[?depth=x]

I always get a
{"allFailedCases":[\{},\{},\{},\{},\{}],
"criticalFailed":5,
...}
whatever depth I choose.

I'd expect at least something like

{"allFailedCases"[{"testcase":"<suite>.<testcase>"}, ...

additional information like [non-]critical, number or repetitions would be welcome.

Pls. document the how to, if this should already work - or fix it.

Thanks in advance

PS: There is a JENKINS-22546 Add REST API to robot framework plugin where this has been mentioned as a comment - but not as a bug. Maybe that's why this is still in.