It's a pity that the case was broken, but it's not a problem because it wasn't an important part.
Works great with my RPi 3b, I selected one of the HiFiBerry DAC options in software to get it going (you can’t presume *any* Pi audio hardware will be automatically recognised). Using it with Volumio, stereo and DTS 5.1 are working fine via TOSLINK optical into an AV amp. I have not yet tried coax SPDIF but very confident it will be fine.
After checking, 'HiFiBerry Digi' is the card I selected in Volumio which got this working. And I am currently listening via the coax output. I get the impression that connecting the coax has disabled the optical, but haven’t investigated very deeply, just that optical works fine on my AV amp but I can’t, it seems, connect both optical & coax then switch between them on the amp, guess I'd have to disconnect coax from the card to regain optical.