Display backlight flashes (usually while stuck on a black screen) if HDR is on

[VisualEhrmanntraut]

macOS Version

None

What is your CPU's model?

n/a

Please describe the behaviour in detail.

self explanatory

What should've happened instead?

normal boot without flashing backlight

If applicable, attach the .gpuRestart, .panic, etc file related to this issue.

No response

[newperson1746]

I commented my experience with HDR in #301 which is slightly different than here. In my testing, HDR on means SetupAssistant hangs at a beach ball. Booting without acceleration and completing setup allows for a flickering albeit successful boot to LoginWindow and subsequent toggling HDR off allows for normal use.

The flickering did not result in a hang outside of first boot in Sequoia. I haven't tested other versions thoroughly yet but can test Sonoma and will test Tahoe soon