Long time lurker, just wanted to say thanks for all the hardwork and share some experiences I had below that'll maybe help someone. My setup is almost identical, except for 16GB RAM and a Samsung 970 EVO Plus. Installation was from a fresh USB drive (UniBeast, then swap in rj510's EFI folder after giving it a S/N), and simply copying over the EFI folder to the SSD after installation made everything work right away (minus WiFi, which I haven't replaced yet).
1. Don't be lazy like me and plug the flash drive directly into mobo vs USB3 headers. The USB3 headers kept giving KPs
2. DisplayPort works at 3440x1440@120Hz (max my monitor supports), haven't tried HDMI
@rj510 - what does your 9900K idle at? In Windows, it's able to step down to 800MHz, but looking at Intel Power Gadget, mine only goes down to 1.3GHz
Also, the mouse jerks around a bit sometimes; doesn't happen in Windows. Will try different USB ports.
*Fixed by moving USB receiver onto motherboard instead of connected to a USB hub