I might have been unclear, I do not want the data back into Roon, I just want it back to the same device, using NAA installed on it and then output using the attached USB Vlink device.
In my case Roon is only used as a front end, and I was thinking that the purpouse of NAA is to have any computer that has HQplayer installed, be able to transport the sound it upsamples to any NAA device (or computer with NAA installed).
So my thoughts were:
Intel Nuc with Linux (Roon Rock) → Desktop computer HQplayer (Hqplayer added in Roon GUI on Nuc) → Desktop Computer (HQPlayer server) → NAA device with my VLink selected as audio device (ideally my Intel Nuc with Roon Rock + added NAA drivers/app).
Accomplishing this by installing NAA drivers on the Linux (Roon Rock) Nuc. If any such do exist for linux.