> # CONFIG_EDAC_AMD64_ERROR_INJECTION is not set

Are you sure those settings are "=y" or "=m") in the other file, and not just simply not present? Changing that one setting may only have altered whether those other settings are explicitly included in the .config file, and not their value.

On the .config that has had CONFIG_CPU_SUP_AMD removed, these settings are no longer present.

My current understanding is that if a particular CONFIG_ option is not present in the .config file, it will not be built due to a missing prerequisite. Do you have a different understanding?