Why bother with trying to put it on a NAS at all? The better and cheaper play would be to buy a NUC (Gigabyte Brix i5 (368.00), 128 GB SSD (45.00), 8 GB Memory (35.98), running Linux w/Roon) specifically to run Roon and then just keep the music on your current NAS. Or if that is too DIY go with a basic (and slower) Sonic Transporter for 375.00 with Roon pre-installed.
Everything seems to be running well for me and following recent updates, I don’t get any drop outs or performance issues. It definitely feels snappier than before and I have been adding more music as well.