@Toad - Thanks, I read your post on
the Z390 and i7-8700K - any successful builds? thread, and it was your post that led me to using the -no_compat_check boot-arg - a big thank you for your help as well. I'd also be interested whether you are using DP output for your UHD 630? In my case, I needed the framebuffer patches to fix the HDMI Black Screen Problem with my UHD 630, once I'd faked its device-id.
I've also just upgraded to Mojave, and everything went smoothly - GPU acceleration is still working. It appears About Mac is more accurate too, after the upgrade, showing both my UHD 630 Graphics, and Intel i5 CPU: