Card profile to split stereo input into multiple mono inputs
I have a USB audio interface that I am using connect a couple of microphones to my computer for use with various applications, including firefox, zoom, OBS, and chrome. The audio interface has two XLR inputs, but it appears as a single stereo input. This problematic as in that configuration, sound from the mic is only provided on the left or the right side, depending on which channel it is connected to. With pulseaudio, it is possible to basically create separate mono aliases for the left and right channels with module-remap-source in default.pa. However, this is also not ideal: the settings are only applied when pulseaudio starts, so pulseaudio needs to be restarted when the interface is plugged in for the settings to be applied. Additionally, this technique doesn't work in pipewire. I have heard that it is possible to work around this by using jack patch-panel tools, but it seems that this method for configuration also isn't persistent and would need to be applied separately to each application, manually applied on boot, and manually applied when the interface is connected.
This would be a perfect use case for card profiles: provide a dual/multi mono input profile in addition to the current stereo/surround input profile, and then the user can select the desired profile in the settings.