Normally it takes 7 to 10 working days to progress to 70%… But sometimes if you are lucky enough it can only take 4 working days to progress to 70% and get the Val… Mine took only 4working days to move to 70% as well…. All the best
For change of course you can remain in the country during the processing of the application. However, you are required to liaise with your institution to cancel your current visa and apply for a new VAL under the new course. The approval to issue the VAL is solely at the discretion of the Immigration Department.