Advice: R-Pi Zero W with optical output

Hi all,

I’m looking on some input to set up a Raspberry Pi Zero W with optical/coax connection to an external DAC for a friend.
I have been running Volumio on my R-Pi Model B with a Schiit Modi USB DAC ever since Raspify, without sound issues. I recently switched to a R-Pi Zero W, and this little thing is more than powerful enough for flawless FLAC playback, incredible! (Especially for this size and price!). That’s why I want to build a similar setup for a friend now. In his case, we want to have a digital connection (optical/coax) though, the reason being compatibility to just about all high-end DACs out there.

So far I have found the JustBoom Digi Zero pHat break-out board. Seems like a perfect affordable little board for the Zero that gives us the desired digital output.

The questions now are:

  1. Is this one compatible with Volumio? It is fully supported in Raspbian and Noobs, but also Volumio?
  2. I would say the critical step in sound quality in the setup would not be this board, but rather the external DAC. The quality of this board is good?
  3. Any alternatives to consider? So far this is the only one I have found that is affordable, dedicated for optical/coaxial output, and even especially made for the Pi Zero (W).

And of course we’re going to have to figure out the casing to neatly enclose the full setup, since there are no standard fitting cases available.

Input would be appreciated, thanks!