It's available via the command line; if your Mac is supported, you can run it as often as you like.

I’ve been running the High Sierra GM since it was released a week ago.

Here's the command:

   usage: eficheck: [ --save -b <EFI bin output file> ]
                    [ --cleanup -b <EFI bin input/output file> ]
                    [ --generate-hashes [ -b <EFI bin input file> ] [ -p <Output folder path> ] ]
                    [ --integrity-check [ -h <EFI hash input file> [ -b <EFI bin input file> ] ] ]
                    [ --show-hashes [ -h <EFI hash input file> ] | [ -b <EFI bin input file> ] ]