My current settings are shown below. Because the Denon does not support DSD format, I’m using the “convert to PCM” option. I’ve also set an upper limit on the PCM sample rate and the bits per sample, because the defaults didn’t seem to work. These could be raised further, I think, but I haven’t bothered to do much experimenting.
At the moment, the music files are stored on a separate server running Windows 10 Pro. This server is used to hold other media files for the home cinema setup.
The Roon Core system in the Akasa case does actually have an internal 1TB drive installed, and I will get around to using this once more for the music files (as I originally did when it was in a previous generation NUC using Roon Server running under Windows 10 Pro). I just haven’t completed the move across to the new ROCK-based system as yet.
Not sure why you’ve been told it’s not advisable to store files on the NUC, I see no reason not to.