Just to wrap this up - I finally managed to get the switch to pair. While watching live logging, I could see that the switch was at least partially pairing with the hub. The switch was getting a device ID, and it was pulling in the proper description and everything. But the switch never popped up in the app (either classic or new) to finish the setup process. So, I cancelled out of pairing and then manually added a new device via the IDE. I gave the new device the device ID that was showing up in the live logging, and everything started working.
I doubt things are set up ideally, but it seems to work so I’ll take it. The raw description field is missing entirely now, so overall I seem to have taken a step back from where I started - but oh well, it’s working at least.