Hey, MaLd0n
thanks a lot, the DSDT works like a charm... I am using iMac19,1 SMBios and I have edited some device-ids (SATA, XHC) to be the same as in the iMac19,1 - that rocks! Also in config.plist I added Intel injection with the iMac19,1 Intel UHD 630 device-ids. I don't need Whatevergreen anymore and my sleep is working again this way. Intel UHD 630 is fully recognised and accelerated. But I am using the Vega 64 as output. The injected ig-platform-id from the 2019 iMac 27" is a headless one I guess.
I also added a ETH1 device with device properties in order to display the second gigabit lan (intel i211 PRO) properly.
Thunderbolt 3 is also added.
I am waiting for the IMEI and XSPI device-ids from the iMac19,1 dump in order to load the kexts for this devices.
Only one thing I would like to improve is to drop the USBInjectAll.kext, even after removing the unused USB2/3 devices in the XHC to the number of 15 (I did not count the two USB3,1 devices) and adding the proper device-ids to the _DSM part, my USB keyboard/mouse is not recognised at all in no port without USBInjectAll.kext. I am not using USB patches to disable ports limit.
You said that you don't use USBInjectAll.kext neither, nor other kexts or port limit patches - can you share your XHC device from your DSDT, I want to have a look on it. I don't understand why mine is not working.
Maybe I will try TeamViewer to explore IOReg on this build from my macbook, but maybe you have other hints?
Thanks a lot so far!!!