I think what I am going to do is file and pay sales tax on Dec 31st in order to go with the preferred method and "deduct" in same calendar year.
That's what I would recommend. Just understand that your payment may not be "credited" until Jan 2 of 2020. Since I doubt you'll be open the 31st, you may find it more comforting to submit on the 30th. Then your chances of it being processed and credited in the same tax year paid are much higher.
But it really wouldn't matter per-se. That's because once you pay it online and effectively lose control of that money, it's no longer your money to claim "as yours" when you submit the payment.
