@Mike Rife,
I also recently "...worked through all -- all -- 94 pages... "
I think, if you want to play DSD, you will need the Topping ASIO driver for best results, but I'm not sure there is one for a Linux system.
Not being a 'Roonerite' I would say it is very likely the D50 will simply be plug and play. The Nucleus is a server, right? Then I imagine it will play just as nicely with the D50 as my Windows LAN does. Better check with someone with a Nucleus, but I can't imagine why there would be an issue.