I primarily use Roon, and noted that the DAC is not yet officially Roon ready or certified or whatever the correct terminology is. But it works with Roon just fine. Worth pointing out that the interface between the internal Pi and the DAC stage is I2S and that link it is limited to 192/24 (will downsample anything above that). Only the USB input will handle all the advertised formats. So as a Roon endpoint understand that DSD and 364/32 PCM won't be handled natively, if that's a concern.
I actually don't use the internal Pi, I have a Bryston BDP-3 connected via USB. I probably should have just purchased the BDA-3 but the 3.14 was only a small amount more money and it gives me options.
There are those that believe the internal Manic Moose interface (or rather MPD) sound superior to streamed from Roon. I believe that is a load of cobblers. To my ear it is exactly the same, but YMMV.
Cheers,
Robert