Ok, great news...
Just updated to 17G2112 on a bootable clone drive and the EFI works perfectly.
Even better news...
After reading a few threads regarding the new native Coffee Lake support I thought I would try it without the injected platform-id etc... worked perfectly.
Next step, tried without WhateverGreen... works perfectly. Audio through DP works too (I don't use it, but thought I would try it)
One snag I hit when updating to 17G2112 was that it completely removed my EFI folder. It was fine as I just used a USB stick I have with a working bootable EFI, but its something to note.
So... TLDR;
Build 17G2112 allows us to use the UHD 630 completely natively with zero additional kexts or injections.