Success ... at the moment.
After getting the 2017-003 security update for El Capitan to install on my Nuc, it wouldn't boot. A recovery install of El Capitan left things bad....namely rolled back to Safari 9.x, and the only update that was offered was the 2017-003 again. So, I took the plunge the upgrade to Sierra.
At first, no WiFi or Sound. Sound was expected, WiFi was....not sure. Also desktop would blank out after about 1.5 minutes, about the time where it would pickup my second monitor. I could ssh in, and everything seemed to be running, but messages about being not entitled for displays or something... Bluetooth appeared to be working though.
I fiddled around a bit injecting different kexts, tried AppleALC.kext/Lilu.kext, but that resulted in a panic boot looping, after recovering from that and in browsing the forums, decided to go with AppleHDA_ALC283.kext from RehabMan's Lenovo-U430-Touch-DSDT-Patch. A couple of iterations of that with more panics or no display, etc. Was about to give up on it, when I decided to try tweaking my SSDT's (namely SSDT-HDEF, changing layout-id 1 to 3) and adding in additional KextPatches from RehabMan's NUC5 guide. The pair that caught my attention were the two antipop ones. While AppleALC.kext got pitched, I threw in AirportBrcmFixup.kext and IntelGraphicsFixup.kext into my inject.
Had started with trying to adapter SSDT-NUC5, but got lost for a bit...and while it compiled, opted to not try it. Had gone back and forth between whether layout-id 1 or 3 was the correct one.... but apparently settled on 3.
Rebooted. and presto, I had sound....and I had WiFi. The display start up is stilll glitchy....it'll start up with mDP (primary) and then about 1.5 minutes later it'll go blank and sometimes eventually bring up both displays, or stay blank requiring power cycling to get displays back (reboot works, but the displays don't come back...something probably still not quite right somewhere...)
So, in the end, only changed SSDT-HDEF.aml (though I had generated a new SSDT.aml, but ssdtPrGen and OS version string differences, it was otherwise the same.)
For kext injection, I previously had:
FakeSMC.kext + ACPI/CPU/GPU/LPC Sensors
FakePCIID.kext + FakePCIID_Broadcom_WiFi.kext
IntelMausiEthernet.kext
Had CodecCommander.kext and AppleHDA_ALC283_out.kext in SLE and BrcmFirmwareRepo.kext/BrcmPatchRAM2.kext in LE.
Now for kext injection, I have took out FakePCIID.kext + FakePCIID_Broadcom_WiFi.kext, and added Lilu.kext, AirportBrcmFixup.kext, IntelGraphicsFixup.kext and LiluFriend.kext....
Switched AppleHDA_ALC283_out.kext for AppleHDA_ALC283.kext (from Lenovo-U430...)
Since I don't use HDMI audio (I did have it working at one time, but abandoned it, and disabled it in BIOS, as having it on prevents sleep and there's no volume control.), so neither the old (0x05 DP to HDMI pipe to 0x12) or new (0x05 DP to HDMI pipe 0x09) are used, and most of the other patches were also tossed, only Trim Enabler got kept from before. What got added were the four AppleHDA ALC283 patches from LenovoU430 (where only two are applicable for Sierra)... AirPortBrcm4360 - fcvo, 10.12.x and 10.11.dp BT4LE-Handoff-Hotspot patches + two AppleHDA anti-pop, and the "AppleHDA ALC262 to ALC283" patches from NUC5.
Oh, and added "Mobile - false" to SMBIOS, though have been trying to figure out if I can get nut to work on it, to maybe to get signaled from my from fileserver when the UPS is about to go down (though I need to replace the batteries in it, so it'll be more than a few seconds...)
Haven't tested Continuity/Handoff, but the tool says its running.... Though instant hotspot doesn't appear....it used to though. (though don't use it that often on NUC, but would be more useful on HP2570.... though I also have a separate LTE hotspot....) Need to get around to installing apps on the laptop someday. Could use some kind of package management tool to keep apps in sync on all three of my Macs or something....
Anyways...can stop running net.tomsick.antipop on my NUC now.
If only Displayport MST worked with macOS....driving both monitors using mDP might work better. Would often get snow at first on wake for the HDMI port....while the mDP display has been pretty solid (though it did take trying 5 different mDP adapters first...)
The Dreamer.