Ran into the same issue on a couple of 840 G8's I was using for testing. "Bios Identity Data Recovered - The BIOS has recovered it's identity data from the Embedded Controller due to a data mismatch."
I figured it was similarly going to require the EC to be either patched or reflashed as well - there's another thread on the 830 G10 where someone else reported the same issue - [url]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/bios-requests-only/3323028-hp-830-g10-bios-identity-data-recovered-while-unlocking#post3323028[/url]...

Morning all - new member, and semi-new to bios programming (have done some stuff with ESP's, but that's about it).

Currently researching for exactly this process - reverting a previously used HP mainboard to a state suitable for putting into a spares pool and then re-dmi when installed into a machine.
Primarily EB840 G7+G8, some 850's of the same, and potentially moving into the G9+G10 models. Business, not consumer models.

This is probably the most relevant thread to ask the question in (and thanks to any that answer)
For the purposes of refurbishing boards...

obligatory post for forum compliance