Failure to write LED brightness values on pmOS-based systems

[BraidenPsiuk]

Can't write LED values on recent gnome-mobile pmOS edge build. May have to first grant permissions similar to this:

echo 1 | sudo tee /sys/devices/platform/leds/leds/pinephone\:blue\:user/brightness

from pmOS wiki section about controlling LEDs for OG PinePhone.

Error is along the lines of "cannot write, invalid permissions".
This does not affect Manjaro Phosh. Not sure if other images like Mobian behave this way.