Thank you for response. I've already reported it through Feedback Assistant - bug FB9778734. It is open and I am waiting for response.

Problem is solved. It is possible to give UID to init function of IOUserAudioDevice.

The question is still open. I need to find answer on how I can decide (based on serial number of device) whether second or next device can be handled by driver. In IOKit I just had to overload IOAudioEngine::getLocalUniqueID and return empty OSString if I didn't want the driver to handle another device.