None of the backlight registers fixes actually work in Sonoma 14.5 with Coffee Lake iGPU

[wolf606]

I've set up this hack yesterday and the first odd thing I notice when booting into the installer was that as soon as the Apple Intel GPU drivers took control of the device, the screen would start flashing. That was using no backlight register fix in DeviceProperties. When I tried the enable-backlight-registers-alternative-fix, the flashing went away. However, the backlight slider in macOS can be toggled and moved, but it doesn't actually changes the display brightness. When using the enable-backlight-registers-fix, the flashing would start again.

Booting into the macOS Sonoma recovery with no backlight register fix
https://github.com/acidanthera/bugtracker/assets/107286189/bd47d89a-fa50-48e6-8966-9c37f5571e48

Booting into the installed system with enable-backlight-registers-fix
https://github.com/acidanthera/bugtracker/assets/107286189/58c944f8-7e79-49a9-b198-0541499aa2ab

Booting with enable-backlight-registers-alternative-fix
https://github.com/acidanthera/bugtracker/assets/107286189/c0c2fdb4-ef13-42d6-a65a-9651d2f27a7f

EFI.zip

Intel(R) Core(TM) i3-8130U
6 GB DDR4 RAM 2400 MHz
Intel UHD Graphics 620 (no dGPU)

Acer Aspire A315-53