- Edited
de0u Documentation is hard to find, but there are many sources of information that confirm this.
For example, there is a paid app made by good developer - Flar2, that helps to enable this High Brightness Mode, and works on Google Pixel devices (but only with Root)
https://play.google.com/store/apps/details?id=flar2.hbmwidget&hl=en_US
(Description from Google Play -Supports Pixel 4, 5, 6, 7 and 8 series (requires root)
-Supports OnePlus 5, 6, 7 and 8 series (requires root)
-Supports most (not all) Samsung devices without root )My photos proving the existence of this mode https://postimg.cc/gallery/cY1vXX5
(PWM decreased and brightness increased)Commands that require root, they enable this mode (atleast on Pixel 6 Pro, but can also work on 6a and other models) -
echo 1 > /sys/devices/platform/1c2c0000.drmdsim/1c2c0000.drmdsim.0/backlight/panel0-backlight/hbm_mode
echo 1 >> /sys/class/backlight/panel0-backlight/hbm_mode
echo 2 >> /sys/class/backlight/panel0-backlight/hbm_modeAnd there's also an article about it https://hothardware.com/news/google-pixel-4-high-brightness-mode
I think that it is not a difficult thing to implement such a simple switch in GrapheneOS, because Pixel devices already supports High Brightness Mode.