HDMI output missing from dropdown

[njam]

My HDMI output is missing from the extension's dropdown, but is visible in system settings. Possibly related to #17.

System settings:

Extension:

[manfreed]

I also have a similar experience.

Here is what I have:

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC3204 Analog [ALC3204 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: H540 [Logitech USB Headset H540], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

See that analog output and HDMI are on the same card?
(I have omitted some more HDMI outputs from my list, I have 7 in total, all of them on card 0)

I think the underlying issue is that this plugin shows the list of available cards and not the devices they expose.