Enable ChatMix and surround sound on the Steelseries Arctis Pro using PulseAudio profile files. Based off the work by Witek094
Copy 91-pulseaudio-steelseries-gamedac.rules to /etc/udev/rules.d
Copy steelseries-gamedac-usb-audio.conf to /usr/share/pulseaudio/alsa-mixer/profile-sets
Copy steelseries-gamedac-input.conf, steelseries-gamedac-output-chat.conf, steelseries-gamedac-output-game.conf to /usr/share/pulseaudio/alsa-mixer/paths/
WARNING: At the moment, you can't use the DAC's "Hi-Res" mode while these profiles are installed (this will be updated when I find a way). To restore original functionality, just delete the files you copied again and replug the DAC