Hmmm. I use Roon and a less expensive streamer (which sounds great). I have a NUC to run the core on.
I didn't think Aurender worked as a roon endpoint. So I am surprised by your setup. Perhaps Roon is seeing your Upsampler/DAC? I know with my USBridge streamer Roon actually sees my M-scaler (like the streamer is transparent).
So I've been thinking about a high end streamer. Leaning toward the Innous because it has an onboard stransport/ripper and so I can get rid of my CD transport. It is also Roon ready. But I don't think they go up to 4 TB.
someone else will have to talk about the virtues of and external SSD drive. I know they all support that but don't know how seamless and quality that is.
Jerry