We have configured our agile boards to do estimation statistics on "Original Time Estimate" and Time tracking on "Remaining Estimate and Time Spent".

Unfortunately the planning screen does not show hours summarized also from sub-tasks. If you do planning (Plan screen) only on sub-task level than the field for estimate (total estimate time) is blank. See attached screenshot.
Also problem here is that if you do not resolve task/sub-task in eg: Sprint 1 and you put it into Sprint 2 it will show original estimate (the one that's done on task level) instead of remaining time.
The same applies to Report screen - Burndown chart. The sum of remaining hours for sub-task hours is not there. Original estimate is used instead.