The GL-iNet routers currently have an option to disable the LED (totally off).
But would it be possible to add an option to set the LED brightness? I'd like to keep the LED enabled to see that the device is on, but would love to make it less bright.
They would likely need to be able to PWM the LEDs, which might not be possible. If it's annoyingly bright, a quick fix might be brightness adjust via Sharpie. Either external,or disassemble and paint the LEDs directly. Easily reversed without damage with rubbing alcohol.