OK, so the nas arrived and I created a virtual machine and installed win10 on it.
I don't think there's anything special about running winmx on a vm and there's enough guides for setting up a vm on the web already.
In my case I ditched the windows vm though and did a linux vm and am now running winmx with wine on the vm like I do on this computer.
Although wine is quite a blob it still needs way less resources than running on win 10 - plus it's free
Now I just gotta find a torrent client I like for the nas and then I can shut down this computer wheneven I don't need it.
Anything filesharing then runs on the nas - mission accomplished !