Note: this is a subquestion of this question.

D3D11CreateDevice can accept the D3D11_CREATE_DEVICE_SINGLETHREADED flag. The docs say:

If you use this flag and your application calls methods of Direct3D 11 interfaces from multiple threads, undefined behavior might result.

At the same time, the Direct3D 11 Threading Considerations page says:

All ID3D11Device interface methods are free-threaded, which means it is safe to have multiple threads call the functions at the same time.

So are “ID3D11Device interface methods” “methods of Direct3D 11 interfaces”? Will the D3D11_CREATE_DEVICE_SINGLETHREADED flag affect the thread-safety of the resulting ID3D11Device?