all depends on your rank
if it was an impossible exam and everyone failed but youre rank 1 and it doesnt represent hsc difficulty then no - but then again how likely would it be for everyone to fail
for discursive i think it would be beneficial to read several examples
also something my teacher recommends is to keep like a short journal, write random ideas you have in it. if you watch a film, write your thoughts on it so that overtime you have ideas to talk about not only in discursive but...
i mostly studied for my accelerated subject - 2u math but for the others:
i went ahead for chem which i also got tutored for, i finished all my chem notes for mod 1 which became pretty useful in the prelims. in the term i dont like updating my notes i like spamming questions so this helped me...