How to get 4K output out of HD630?

Hello lovely people,

I built a computer this weekend motivated by all the amazing progress that this community has made and wanting maximum bang for buck:

Gigabyte Aorus Master (BIOS F11c)
Core i9-9900K
64GB Kingston HyperX Fury DDR4
Samsung 970 Evo Plus 1TB SSD

I followed the OpenCore vanilla guide, installed and running 10.15.3 successfully. I'm on OpenCore 0.5.5 and all latest kexts / Drivers needed for CoffeeLake, as well as the four recommended SSDTs and a custom USBMap.kext provided by someone else for this motherboard.

As far as I can tell, everything is working fine, except the iGPU is not outputting 4K to my external display.

I have the correct Framebuffer data in the config, DVMT is at 256MB pre-allocated and MAX total, I've mapped the correct bus for the built-in port, I'm using a WEG flag to enable 4K/60fps (-cdfon) but nothing seems to push the card over 2560x1440 output.

I've been searching for the past two days but no solution seems to work. Has anyone figured this out?

Once this last step is done I plan on sharing a guide along with a complete EFI setup on GitHub, to do my bit for the community.

Thanks in advance!