Thank you again. I rescued my X1 Nano today. I had to hot air the BIOS chip off and solder it to a CH341A (underneath on the SOIC8 pads), and it fought me still.

I erased it, then tried to program and instant verify fail. So I turned off Verify in the top menus (ASProgrammer 2.02). Then programmed it and read it back, it was still a fail, but I wrote it again and then the CRC-32 matched the one 7-Zip showed for the BIOS .bin file

(I used the read button and it gives the CRC-32 in the log window of ASProgrammer when it finishes, takes ~10 mins!).

Cheers...