@ AJR
I previously had the Lumin A1 and (still have) a Synology NAS and had gotten used to the Lumin app and user interface (although the Linn Kinsky and now the fidata apps work quite well too).
# uPnP / OpenHome / Lumin app
The Lumin app is an OpenHome app. Based on the user manual for version 1 of the MSB renderer module (
www.msbtech.com/support/RendererManual.pdf), it is uPnP compatible but it is not (yet?) OpenHome compatible, so it would not be possible to connect the MSB and Synology NAS via ethernet and still be able to use the Lumin app. Things could be different for version 2 of the MSB renderer.
I discovered this uPnP / OpenHome distinction when trying the Weiss DAC502 with my Melco N1A (soon be replaced with the N1ZH).
# Using Lumin app with compatible server and USB
Otoh, with my Melco N1A running MinimServer, I was able to use the Lumin app when the Weiss was connected to the Melco via USB.
# USB vs ethernet inputs
While I was happy to be able to use the Lumin app through the USB output of the Melco, on extended listening, I felt that the ethernet input of the Weiss DAC502 was better than its USB input, even when the ethernet connection was handicapped by using an entry level LAN cable (Supra Cat 7) vs a high end USB cable (Acoustic Revive).
Therefore, if it is possible to extrapolate, subject to the usual YMMV caveats, the ethernet input of the MSB is likely to outperform the USB input.
# ROON with Synology / QNAP NAS
I understand that is now possible to run ROON in a Synology / QNAP NAS, depending on the specifications and processor used. You might want to explore this option.