For some reason there are a bunch of people on this forum that think flashing firmware is dangerous. I have literally flashed ten thousand plus bitmain units and have never bricked a machine with a firmware update. Im betting that a lot of people flashed incorrect firmware because they are too impatient to confirm they are using the correct one and blamed bitmain instead of their own incompetence.
If you are receiving machines from the November batch they will most likely already have the most current firmware. I have even received some that had newer firmware than what is offered on the bitmain support site so the chances are you wont need to update yours.
I wholeheartedly agree with you. Where can one get the November or December firmware?
Bitmain's site has Apr 2017 as latest version.
The newest firmware is at the bottom of the page.