Thank you, thank you, thank you. Works perfectly with the Cooper and Hunter mini-split I installed in my garage.
I ran midea-discover in a docker container on my NAS (don't normally use Python). It didn't find my unit, but probably because the UDP packets don't reach the IOT subnet the a/c unit is connected to. However, it was a fairly simple matter to find the ip address of the unit in my router's UI, and then running midea-discover --ip <ipaddress> found it and returned the needed information.
For anyone wanting to add wifi control to one of these Midea-manufactured hvac units, the dongle is apparently a generic module. I took a chance and bought the Pioneer branded one ( Amazon.com: PIONEER Wi-Fi Remote Programming and Access Module for Pioneer WYS Series Heat Pump Systems : Electronics) and it works fine and was $30 cheaper than the Cooper and Hunter branded one. The model numbers (OSK102) are identical.
Now just waiting for a Sonoff temp/humidity sensor so I can turn the unit off after humidity drops to a certain point. The unit has no humidity settings or even a sensor so in "dry" mode it runs 24/7, often turning my garage into a refrigerator.
