They know if normal eVAL takes too much time the student can go somewhere else but if you are applying for eVAL extension you are already a student and thus have completed a semseter have also most likely paid uni fee so now you are invested and cannot think about abandoning studies thus they can delay and see how much mental torture can the student sustain
We understand your concern. Please note that there is no stipulated timeframe for VAL extension processing. The approval is solely at the discretion of the Immigration Department. You may refer to the Immigration website for their contact details.