Disabling the LED on the UDM was surprisingly annoying.

curl -k 'https://192.168.1.1/proxy/network/api/s/default/stat/device' -H 'Cookie: TOKEN=<token>'  | jq '.data[] | select(.model=="UDM") | ._id'

curl -k -X PUT 'https://192.168.1.1/proxy/network/api/s/default/rest/device/<id>' -H 'Cookie: TOKEN=<token>' -H 'X-CSRF-Token: <csrf-token>' --json '{"led_override": "off"}' 

Much thanks to finding this as a reference: https://github.com/ameyuuno/docker-unifi-led-light-switch/blob/master/src/unifi_led_switch/unifi.py

@alpha I usually disable/dim LEDs with electrical tape

@drbrain I do have sheets of dimming cling film for this purpose! But the UDM’s LED is kinda awkward to physically obscure: https://store.ui.com/collections/unifi-network-unifi-os-consoles/products/udm-us

@alpha oh, right! I forgot it was a giant ring