How to choose fonts with different optical sizes with fontspec

Question

The font EB Garamond is a font that provides (at the moment two) different optical sizes. The fontspec package will automatically choose the appropriate optical size (cf. the manual under section 8.6.).

But how can one do this when fonts are explicitly selected with path specifications? In the first MWE below, fontspec loads the system font EB Garamond, and notice the differences in the fonts in the tiny size and the normal size. In the second MWE, fontspec loads an explicitly declared font, and in this case, the font is simply scaled down.

\documentclass{standalone}
\usepackage{fontspec}
\setmainfont{EB Garamond}
\begin{document}
{\tiny{1234567890}}
1234567890
\end{document}

\documentclass{standalone}
\usepackage{fontspec}
\setmainfont
    [
        Path = M:/MyStuff/Fonts/EBGaramond-0.015d/otf/,
        UprightFont = EBGaramond12-Regular.otf
    ]
    {EB Garamond}
\begin{document}
{\tiny{1234567890}}
1234567890
\end{document}