A bit more of an update: I found this guide to the RAK881 AT commands RAK 881 AT Commands V1.4 which seems a bit more helpful that any of the other docs. A few commands from there also work, sich as:
at+band
OK.EU868
at+get_config=dev_eui
<deveui>
Note that none of these are in quite the same format as documented elsewhere, and don’t require “lora” to be included.
BUT: - I still can;t work out how to set the app_key, which I need to be able to configure the device to join using OTAA
Even so I have so far only manages to get to to run in ABP mode - in OTAA it just comes up with “No OTAA Parameters” even though I think I’ve set them all.