The “iqaudio-digi-wm8804-audio” is missing the “alsacard” setting, that is why it will not be listed.
The alsacard value should be “IQaudIODAC”, identical to the other two.
Like this:
{"id":"iqaudio-digiplus","name":"IQaudIO Pi-Digi+","overlay":"iqaudio-digi-wm8804-audio","alsanum":"2","alsacard":"IQaudIODAC","mixer":"","modules":"","script":"","needsreboot":"yes"},