Great job, smp.
Your 26/1 image runs perfectly on my GLK Beelink (X55 & X45).
NVRAM & bios side effects while testing 24/4 and/or 1/2 kwiboo images, so i lost ALSA AZALIA even with DSP Disabled.
Got fine again after a bios Reset to defaults & rebooting 26/1 live again.
On LG OLED B9 i can play Atmos (upto 5.1 channels) with all my DV/HDR10+ samples (1/2layers) going out with HDR10 then Atmos pop-ups !
So it is pretty amazing to finally get HDR+ATMOS in less than1 hour, in comparison with a month of unsuccessfull struggle inside intel drivers collection (from 6912 first called supporting HDR on FLK, to even this late april all iGPU chips driver)....
Within win20H1 all seems working (such SGX, PAVP, TPM/ME, HDCP22, ...), but I never got "Advanced Color" set in directX diagnostics, neither with os Settings nor Intel RGB/YCbCr Configuration variations appx.
So your job all of you at LibreELEC is a fantastic help for people whose config don't use Nvidia output & drivers for hdmi 2.1 LG TV.
Thx for your PoC, finally a cheap solution unexpected !