I would definitely not spend less time on that. The awa section actually comes quite handy because it starts to let your brain work with not too stressful and time pacing tasks.....
Some people say, that reading some pages of a book before the test does the trick. However I personally would drift off a little. I always get so involved reading a good book
And I dont really think that the AWA takes so much of your brain power, that you may perform less in the quant and verbal section. Its part of the overall gmat. Your gmat essays (not only the results) will be sent to your schools. The admissioners will read them, so you want to make sure to demonstrate some writing skills.
Additionally, they sometimes want to double check your writing style with your essays....
Do what feels comfortable, if you think your Awa essays are fine, move on to quant.
Good luck for the test!