For users who have trouble running Roon on the M1 in exclusive mode, whether over HDMI or USB-C/Thunderbolt-HDMI, a solution is to be found here: Audio device in use - exclusive mode - #3 by Richard_Elpers.
For users who have trouble running Roon on the M1 in exclusive mode, whether over HDMI or USB-C/Thunderbolt-HDMI, a solution is to be found here: Audio device in use - exclusive mode - #3 by Richard_Elpers.