In https://doc.coreboot.org/releases/boards_supported_on_branches.html#id8 , Coreboot hints that patches can be added to the Coreboot 4.8 branch that the KGPE-D16 and similar computers depend on: "Patches can be backported from the master branch to any of these other branches as needed. The coreboot project may take care of backporting critical security fixes, but other patches will need to handled by anyone using that release.".

And we have an important patch: "c18e785 ressources/coreboot/fam15h*: fix building crossgcc 8.3.0 (fixes #64870)".

So we could send it to Coreboot.

Since we already have proper authorship and signed-off-by anyone can send this patch to Coreboot (not just its author / backporter).

Denis.