Yeah, as far as I can see it's the native Apple KEXT for NVMe's which is causing the kernel panic, not something added by Clover - it looks to be an Apple specific issue, rather than related to it being a Hackintosh.
What do you mean by kexts fresh from their git repository, who's git repository and which kexts?
I'd expect us to have to wait until either Samsung release a firmware update, or until Apple release a fix. I checked the Samsung Magician software in Windows and there hasn't yet been a firmware update for the drive.
I've not tried any of the OSX betas, as I also use this machine for work, so I'd rather not mess with it too much :\