I got home, plugged the adapter into my iPod, then the HDMI into my TV to test. Voilà. In all its crunchy glory. I unplug and replug the adapter, and...nothing. Black screen.
I checked every tweak installed, tried rebooting into safe mode, I could not get it to function again. I tried plugging my iPhone X into the adapter and that worked fine, so what gives??
Eventually I tried restoring the iPod back to the same firmware, and it worked again. Hmm...
I saw in one of the comments on that Panic blog post that, when you plug the adapter in for the first time, the OS looks online for a firmware update for the adapter and installs it, which overrides the old adapter firmware baked into iOS. When you reattach, it uses the new one.
I unplug, replug again on a clean iOS install and sure enough, it doesn’t work. Something in the new firmware is incompatible with iOS 6. I took a look at the system logs to see what was going on: