Audio: Way to disable HDMI or set USB as default?

[Tim Curtis]

It works the same on pi5.

The one used for testing below already had an Allo Boss DAC (I2S) attached.

Starting configuration: Allo Boss DAC (I2S)
   

Plug in USB DAC (assigned to ALSA card 3)
   

Set it as the Output device, play some music
   

** Reboot (USB DAC still on)

After reboot (dynamic ALSA card reassignment 3 -> 0)
Play some music
   

Unplug USB DAC (ALSA card empty)
   

Plug USB DAC back in after some time
Play some music