Well, to get to the state I’m in now (bricked), I used the Windows EXE (Express BIOS or whatever) method. I’m not sure if the other BIOS update mechanisms wouldn’t have had this problem or what. I suspect it wouldn’t have made any difference at all, as the other systems upgraded to 0131 no problem.
I tried to use the recovery method (USB key with 0122 .BIO file on it, pull the BIOS recovery jumper) to get out of this situation, but I don’t think the system even gets far enough to attempt the recovery… There is absolutely no video signal after turning the system on, and it never does anything… I never see the LEDs light up on the USB key, and it never shuts down, etc. It is bricked. So, unless Intel comes up with some method to get it out of this state, my two boards are likely going back under warranty.