Not working for me (upgrade from Sierra or clean install), latest Clover, I believe my Radeon 7750 is the culprit, various fixes (verde.kext, patched fakesmc or lilo + green) don't work for me in High Sierra it seems. Anyway, it will work eventually, I guess I have to show some patience until 10.13 is properly released with unibeast, multibeast and stuff.
I use smbios mac pro 5,1 but that was a no go due to firmware, so tried mac pro 6,1 which allowed me to try to upgrade.
- re-download the new full installer, extract apfs.efi, and copy into various clover installs for the next time
cp /usr/standalone/i386/apfs.efi ~/Desktop
Install CsmVideoDxe.efi EFI driver for clover. Of course, CSM should be enabled in BIOS. Check for possible caveats