I know it’s not what you want to hear but he simplest approach (which will also give optimum sound quality) is a NAS drive connected to the same switch as your Streaming DAC, Upsampler or NB.
Both Qnap and Synology (as well as many others) have the ability to run apps such as MinimServer so no additional computer is required and you will be able to use Mosaic to manage both playback and the connected dCS unit/stack.
Or just Roon Nucleus for $2-$4k + subscription (less, if used). After all, you are just passing bits to a buffer… (Writes this and runs for cover!) ; )
With respect to the transport market, I note that as of today, January 29, 2025, there are an astounding seven used dCS Vivaldi products with transports for sale on Audiogon: two Vivaldi Ones, and five pure transports (!)
I’ve never seen that before…
No need to run for cover 
Here’s what dCS has to say about Roon (from the Varèse documentation).
The Varèse system is Roon Ready.
Being Roon Ready means that your Varèse uses Roon streaming technology, for an incredible user interface, simple setup, rock-solid daily reliability, and the highest levels of audio performance, without compromise.
(Bold/Italics for emphasis)
Anyone who believes using Roon compromises sound-quality should reevaluate their perception 
Perhaps that means that there are now seven owners of Vivaldi stacks who have upgraded to Varèse…? 
This is a bold statement as Mosaic definitely is more transparent on my Rossini Apex versus Roon. I wish it weren’t true as Roon is fantastic in every other category but the difference is there.
**Maybe it is different on the Varese but I think we should be careful about making this statement.
Unfortunately Lee, there’s clear objective proof that there’s no difference between Mosaic/UPnP and Roon/RAAT (at least when both are operating properly) on V/R/B/L (which is clearly the basis for dCS’ statement extended to Varèse).
If you think you’re hearing a difference on your Rossini, either there’s something wrong with your Roon setup, or your biased subjective impression of Roon is manifesting in an “audible” difference.
What are you basing that proof on?
The following post, and thread covers it;
Thanks @Anupc for referring to your post and that thread, and I think it is best we get back on topic here.
The new 15 pages review of the dCS Varèse by The Absolute Sound:
Another review in the Hifi +, issue 241 March 2025
Likely to be the same review as the TAS one, seeing that HiFi+ and TAS share the same publisher.
Different writers, Jacob Heilbrunn for TAS, Alan Sircom for Hifi+
And here it is!
Thx, already read the article in the hifi+ earlier this week, but good to have it here on file
Thanks for posting Erno.
Excellent review by Jacob Heilbrunn. (The other one, not so much )
One thing I discovered recently is that my use of a current model MacBook Pro for the core is impacting things. I hope to try a Roon Nucleus soon and hear if that eliminates the sound quality gap I am hearing.
As the Luddite here, I still play discs for critical listening.
I don’t stream anything, at all. I have no streaming subscriptions whatsoever.
When I find music I want, I buy a CD (or LP), sometimes a SACD.
Lee, best to take this to another thread. It has nothing to do with Varèse.