I might be wrong, but I believe there is a documentation error on the LED signaling enum.
I am working on custom LED signaling for BLE (flashing when scanning, breathing when connected, etc). To do this, I am just assigning a higher priority to my statuses to override the default behavior. According to the LEDSignal Enum docs, breathing cyan (connected to cloud) has a “Background” priority, so a “Normal” priority should override it. However, that’s not the case. I needed to assign an “Important” priority for my status to override the breathing cyan. It seems to me that priority for LED_SIGNAL_CLOUD_CONNECTED is actually “Normal”, not “Background”.
I have not done extensive tests, but I can confirm this on an Argon running Device OS v1.5.0