No support for Manjaro here. There is no enabling ProtoDAC. It does not identify itself to the OS. If you can have Manjaro output I2S to the GPIO, ProtoDAC will work. Set it up for a generic I2S DAC.
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5
Software: Moode 8.3.3
Source: Win 10 NAS
Software: Moode 8.3.3
Source: Win 10 NAS