I can confirm that flashrom does say, "VERIFIED" at the end of a -w operation. I experimented with hot-flashing a coreboot.rom into a spare flash chip (PMC Pm49FL004). I'm using the 'top hat' method of chip extraction. The coreboot rom isn't working yet, I need to work on that some more. But I kept my backup vendor BIOS.
Thanks -Mick