The AWA section completely depends on the school/program you are applying to. That said, you should aim for the average or higher (4.5 or more). Also, if the school or a scholarship demands it or posts the average, please try to reach it. Overall, it is true that it counts for less as you are already probably writing a statement of purpose/letter of intent, but some programs look at it as part of your General English abilities in writing - even though in truth it shows very little regarding your writing skills.

Finally, at least familiarize yourself with the basics and practice a bit! Learn what you need to include in the essays and how to organize them. It would not look good if you get a 2/6. It can send the wrong signal (unless maybe you get a 750!).

The AWA is a murky area and in truth, it does not always carry the same weight as the multiple choice sections but do your research into what the school asks for and what past students in that program are saying/how they had fared too.