The FiiO M11 can not be used as a Roon Core. For more information about what devices can be used as a Core machine, please see this article in our Knowledge Base.
Was that the question he was asking? The way I read this is that the OP wants to use the library on his M11. His Core is on his Mac. If the M11 is connected to his MAC via a cable can the library on the M11 be used by his Core to listen to music is the way I read this question. Perhaps I am mistaken.
I know I can access my library from my Mac core, but hoping it might be possible to access the M11 library when away from my Mac. Both my Mac and Roon libraries are the same.
Sorry, meant to say that my Roon Mac library is the same as my FiiO M11 library. Would be nice to be able to use Roon away from home with just the FiiO M11.