Here is a nice tip that I use on my Netgate SG-3100. I don’t like the bright pulsing blue LED light on the front of the box so I turn it off.
Use this Terminal code to do so.
gpioctl 2 duty 0
You do have to run this after an OS update every time though.
Source: https://forum.netgate.com/topic/123213/can-i-turn-off-the-sg-3100-s-blue-indicator-lights/3