Hi @chris — Welcome! 
You are not the first to notice that the cellular-only queue doesn’t show up in the API. It’s not a bug in your code; it’s a feature we haven’t finished building. 
Check out this thread for more info: Spotter_tx_data possible bug - #4 by zachary
Spotter is a complex product with multiple MCUs. The main Spotter firmware repo is closed source. Let us know if there are logs you’d like to understand better. You may find our SD Card Data Guide helpful. You can get there by going to the Sofar website → clicking support → click the button under “Spotter Documentation & Onboarding” and scroll down to the heading “Onboard SD Card Data”.
The bm_protocol github repo contains the open source firmware for one of the MCUs inside the bouy, the Bristlemouth Bridge. You may find that some logs you’re investigating come from the Bridge, so it’s often worth searching the bm_protocol code.
The “cellular with Iridium fallback” queue does send over cellular if the device has a cell signal. If the Spotter is going to send data from this queue over Iridium you should see in the logs at some point:
Falling back to Iridium modem
As well as
Entering Transmit Iridium State, powering down notecard
Hope that helps!