XPS 12 (9Q33) A07 BIOS update problem

I saw there was an update to my XPS 12 (9Q33, Mid 2013) BIOS about a week ago and decided to install it at some future date.  Well today is that future date, and I now regret having done so.  As you can see in this picture of the screen (with some minor photoshopping to protect my privacy) it shows 59% programming EC.  As I type this, it has been stuck at that point for the last 35 minutes with the fan running very loudly.  EDIT: Correction, I just checked and the clock has advanced as has the progress bar, but only to 65% and that's after roughly 40 minutes (difference between that desktop gadget's displayed time, and the system tray time).

I have unplugged the system from power and am now waiting for the battery to die out so that I can determine if my XPS 12 is dead as a brick.  Dell, please remove the A07 BIOS update from your site, because as I, and the others who have posted here about this exact same issue have discovered, is clearly a bad update that does bad things to those who install it.  I wish I had searched this forum first, and avoided this awful mess.

Now, to the inevitable question regarding my installed video driver version, I don't know what it is, and it may be hours before I know what it is, assuming the laptop works again at all.  My best guess is that it is the one currently available on the support page (XPS-9Q33_Video_Driver_1N5FK_WN_10.18.10.3574_A04.EXE), since it appears from my included picture that I downloaded a file on June 27th that is roughly the same size as that file released on May 28.

If the system does boot up, I intend to revert to the A06 BIOS to avoid the issues that others have experienced with A07.