As for me, with my configiration Apple Thunderbolt display works without any windowses!!!
I have not installed any windows since connecting Thunderbolt Display!
(But any ports, sound etc is not working on display, even camera)
On the picture there is not suited card - do you push it fully down?
Also, try to detach SATA drives for test, some MBs has connectivity between SATA and something other (as I remember PCIe ports). That means if certain PCIe ports are not busy then SATA 5, 6(for example) are not working, maybe...
I have gigabyte z77p-d3 motherboard. Everything works well before current restart.
After it I can't see SATA HDD's (starting from PCIe nvme drive).
What happened? How to help my Mojave to see attached devices?
P.S. USB HDDs are still working; also - HDDs are visible in Clover during boot time...
I'm using KCPM utility now. Sometimes I have no image on display in Mojave, I connect remotely start KCPM Utility Pro – Repair file permissions on the target volume. Then restart and I have image on the display.
I tried to set IMEI on my GA-Z77P-D3 series 7 chipset, but it doesn't start (some Apple HDA problem).
If I try without IMEI it starts but not kext loaded for HD4000. How to load them?
I want to use this iGPU together with HD7950 or GTX 760 dGPU.
Also, no ig-platform-id works, neither 01620005...
Are you using 9900K?
1) Make backup of the whole working EFI directory.
2) It is not 18,3 SMBIOS, try to change to iMac19,1.
Also, experiment with iMacPro1,1 SMBIOS because you are using Vega grapics card.