Brian,
I’m truly happy that I can be useful in your audiophile journey.
Yes, exactly. When you listen to Qobuz using the Mosaic app the music flows from the Qobuz server through your Rossini’s Mosaic board into the DAC. When you listen to music from the Synology it gets processed there to be sent through your local network to the Mosaic board.
Yes. Both Innuos Statement and Aurender N20 have internal storage options. For data migration it’s a good idea to use a specialized software. This type of application handles hiccups and conflicts better than file explorer or finder. Also, this is a good moment to update or adjust the data backup strategy. Pete @PAR has a good cloud service in Britain. I’m using one in the US - Backblaze. Their backups are reliable, but retrieving a backup from them is a pain.
Yes, that is the case - no impact in that scenario.
I would add a good power supply to your TrendNet Media Converter that is connected to your Rossini.
The above article mentions optical media converters and the issues with them. Hence my recommendation to get a good power supply for your converter. A number of other community members use these converters too and they work just fine for them. I would speculate dCS has seen too many support cases in their inbox that have led back to such devices. Also the article is dated 2018 - whatever that might say…