This could happen either through somehow getting logging from the Windows end, or somehow changing the UEFI to be one you control and logging there, or finding a different BIOS/OS that can read the vars and getting it to log its work.
The userspace interface is somewhat documented by third-parties (because it is technically internal). However, the important parts happen kernel side, and I'd rather avoid diving too deep into Windows because some very interesting job postings (understandably) have "No exposure to Microsoft code or reverse-engineering of Microsoft software" in them.
I already tried getting to the service handler implementation via Linux, but memory protections made it weird enough that I was even questioning whether it was returning correct raw data when trying to read it from memory (or I have been looking at the wrong set of headers).
To the untrained layman like me, this sounds like Windows actually is querying via `GetNextVariableName`, because UEFI doesn't seem to offer any other interfaces that aren't "get/set variable by name".
wouldn't that be trivial simply using a VM?
I don't know a thing about BIOS internals, so this might be completely irrelevant