I don't think it is too "low-level", most probably none of the geniuses at Intel and MS thought it was useful and didn't provide a "handle" or "hook" to get it.
My guess is that - like *anything* connected to the stupid EFI/UEFI - there is a mis-understanding/mis-definition (as it is "normal", noone in his/her right mind will ever read 2200 pages of specifications, and even if he/she does, succeed in making anything compliant, as the probabilities of a misunderstanding are very, very high), and BTW they cannot avoid making any number of updates/revisions:
The number that you are looking for and obtain with "ver" in the UEFI shell has seemingly nothing to do with the "version" that you can get via WMIC or similar, basically because (as per your screenshot) it is NOT called "version" but rather "EFI Specification Revision" (aptly called in the above official link "UEFI specification version".
I expected that Windows Management Instrumentation had a field for that (at least on 8 and/or 10), but evidently there isnt one.
Maybe - just maybe - there is something of use in the UEFI Test Tools (the thing that only one line below is renamed to "Self Certification Test")
Under Linux, you may want to try/look for efivars/efivarfs, but again no idea if it exposes the specification (version or revision) as a variable:
should list all variables available, but then most will need to be "decoded" in human readable form.