It's SSDT-USB.aml (which I guess it what you were using to configure USB ports but now use a kext plist?).
And, yeah, according to the KabyLake docs, it's only SSDT-EC-USBX.aml that's needed (https://dortania.github.io/OpenCore-Install-Guide/config.plist/kaby-lake.html#acpi).
I'll clean things...
@pastrychef, I can confirm that this approach works for the IX Hero:
I kept the following in the ACPI directory:
SSDT-EC-USBX.aml, SSDT-EC.aml, SSDT-PLUG.aml, SSDT-USB.aml
Didn't change any of the ACPI > Patches
Removed all of the DeviceProperties and added an entry for using the iGPU...
I downloaded the OpenCore 0.6.2 ZIP file for the Z370-G and installed it on a Catalina USB thumbdrive built using gibMacOS. The OpenCore bootloader starts, but none of the boot partitions are visible. The only options that I see are to reset the NVRAM and the check that MSR 0xE2...