I have the latest CLI, and the dfu-util, so I tried the firmware update that way.
New firmware is here for anyone looking for it!
I was able to upload the new firmware to the Xenons but the Argon bricked after the update.
There’s a thread about resetting the bootloader to fix bricked modules, but I lack the Segger tool to get at the nRF.
I have a new Argon on the way. 