If you upgrade your Router to a properly configured AC router, then that should give you enough Bandwidth to
a) Send the DSD 256 files to the MBP for Roon and HQP to perform the decoding and processing etc…[DSD256 will take up about 23Mbps in streaming the files from the USB Drive to the MBP]
b) Depending on what you are doing within HQP, that SHOULD still give enough Bandwidth for the MBP to send the Data Stream back to the Router
An AC Router over the 5Ghz band and 3m away from the Mac client SHOULD be able to transfer 300Mbps plus, even in full duplex mode
So IMHO, you shouldn’t have any problems transferring the Streams to and from the MBP to the Router over Wifi
And then, the Router can send the Data Stream via Cat X cable along to the uRendu and your System
Personally, I’m not the biggest fan of attaching USB Drives to Routers…historically, there always seem to be a bottle neck and resultant problems with performance
Looking at the Amazon UK website, the Synology 1900AC you mention above is £120…and to that you would need to add approx £80 for a 2Tb Portable USB Drive [to allow for future expansion of your library]…this is a total of approx £200
Given your preference for Apple products, have you considered the Apple Time Capsule 2Tb??..This is approx £215 from the same site…with the big advantage being that the storage is INTERNAL to the Router, meaning faster and more reliable performance…plus a neater package of just one device
There are also All-in-One devices from Synology and WD [and others] but I’m mentioning the Apple one as that may suit your eye more
This was the first thing I’ve been planning to buy — Time Capsule, but I’ve seen the tests of it against an attached storage to USB of Synology 1900AC and it trumps Time Capsule !2 times! despite it’s internal storage…
Actually I’m thinking to get a Synology DS116 and a new router, maybe a Nighthawk or whatever will be as close as possible to 1Gb wifi and as stable as Apple’s routers.