Turn blink notifications on/off
Open Screen & Lock > under Notifications, turn Blink Notifications on or off.
If your device has a notification light, it blinks while the screen is off and a notification is waiting. Blink notifications are on by default.
To choose the color, see Choose a notification light color.
Checked against the LuneOS code and installed apps. Nobody has tried these steps by hand yet, so tell us if something differs.