Hey! Got the Deskmini yesterday. Got it working today.
Once you update the BIOS to the one posted in this thread, the installer will boot. After installation, Multibeast can take care of everything (UEFI, HD530, LAN kext is the latest one of the Intel drop-down list, and the sound procedure by mopidicks works perfectly).
I had to edit the clover config for the HD 530 glitch as covered in other threads.
Everything is working now, Sierra is rocking on my new Dell 4K monitor through DisplayPort.