Thanks @AG7GN your solution shows promise. At least with that I can now share the digirig with direwolf and fldigi (though I don’t know why I’d do that at the moment).
So performing your hack, I can set:
ADEVICE digirig-rx digirig-tx
in direwolf.conf.
However, the problem now lies with Wine and VARA FM. Wine only sees the hardware input and output selections, and does not distinguish between the ALSA PCM interfaces. Any program uses digirig-tx or rx, and the hardware resource is “Busy”. Native programs can apparently simultaneously select digirig-tx/rx but Wine apps cannot.
I did see that one can use winetricks to do something like:
winetricks sound=pulse
to set the dropdown in VARA FM for selecting Pulseaudio, but that only allows me to use PulseAudio on the default channel (the built-in mic/speaker). Now I need to figure if I can bind pulse to the USB PnP Sound Device instead of system default.
To get a complete list of what winetricks can set sound to do:
winetricks settings list | grep sound