Stephen, you may wish to browse this sub-forum … QNAP/Synology NAS - Roon Labs Community which is dedicated to running the Roon core on a QNAP or Synology NAS.
I believe that the Roon Core app for QNAP is only available for the Intel processor models such as the TS-451, your NAS’ have ARM processors ?
Specifics for getting all this to work with non-Roon ready Naim kit are covered in this topic … How can I get my Naim ND5XS network player running with Roon? - #22 by simon_pepper
Nick