Audiocard device is split into multiple PipeWire inputs and reports "[ALSA UCM error]"

[GitHub issues - opened <github@alsa-project.org>]

alsa-project/alsa-ucm-conf issue #856 was opened from artom76:

Hello,
I am having a problem with a Steinberg UR44C USB audio interface on Fedora 44.
My goal is to use the UR44C with FL Studio running through Wine/Bottles and record from multiple physical inputs at the same time. I am using PipeASIO as the ASIO driver. The UR44C itself supports 8-channel capture. ALSA can access the device as an 8-channel device, but PipeWire does not expose it as one 8-channel input device. Instead, PipeWire creates multiple separate input nodes, for example:
alsa_input.usb-Yamaha_Corporation_Steinberg_UR44C-00.HiFi__Line3__source
Steinberg UR44C [ALSA UCM error] Front 1

There are also additional nodes such as "Front 2 & 3" and "Front 3 & 4".
All of these UR44C input nodes contain "[ALSA UCM error]" in their description.
This causes a problem for PipeASIO and FL Studio. Instead of receiving one ASIO device with multiple input channels, FL Studio sees the inputs as separate devices/nodes. I need the UR44C to be available to the ASIO layer as one multi-channel device so that I can record several inputs simultaneously.

PipeASIO itself is installed and working correctly. FL Studio can see PipeASIO, and I have already tried increasing the number of PipeASIO inputs and changing its input/output configuration, but this does not solve the problem because the UR44C inputs are already split into separate PipeWire nodes before they reach PipeASIO.
What I would like to know is whether the current UCM configuration for the Steinberg UR44C is incorrect or incomplete, and whether there is a recommended UCM configuration that exposes the UR44C capture device as a single 8-channel PCM/device instead of multiple separate nodes.

Thank you.

Issue URL     : https://github.com/alsa-project/alsa-ucm-conf/issues/856
Repository URL: https://github.com/alsa-project/alsa-ucm-conf