For this i used a DMX music player in the past:
https://www.ulrichradig.de/home/index.php/dmx/dmx-rdm-mp3-player
That works well for any kind of DMX desk.
Now i have a FLX S48 and a chamsys MQ70. And chamsys can now easy play any standard audio file in a cue list. You can use it with the PC or mac software with a soundcard or with the direct audio out of the lightningh desk. So it is very easy now. Save a cuelist, select the sound file from the internal memory or a usb drive. and when the cuelist starts the audio plays as well. You could also use this to programm timecoded cues to audio files.
Perhaps it would be possible with phantom ZeroOS. Or you could support USB soundcard for the desk as well. That is also possible on chamsys now. So i would call it a feature request 😉