Getting data, submitted by user task

Continue my quest with doing additional work with data, submitted from a user task.

Currently using an @EventListener(DelegateTask) to get to the right spot.
Even found a FormService.getTaskFormVariables, which worked well (or at least at that moment I didn’t spot the problem), but now I realized that it returns All variables, instead of the ones, which were submitted in the current form.

So the question is - how to get a field:value map of the submitted form?