AHA!!!
.. Can't show you any of the results, yet, though, as the entire framework's graphical stuff is currently all commented out, until I convert everything from GLFW to GLES.

But that's a VERY important step in getting the thing up and running on iOS.
Previous attempts have spewed out thousands of Linker errors, but now I'm fairly confident that I vaguely might maybe know, roughly, what I might have been possibly doing wrong!!

.. I think!

There's now "only" 44 warnings to work out, but most of those are actually coming from lodePNG and the Ogg decoder stuff, so aren't my fault!!
I'm currently thinking I might need to add mp3s into the mix, for iOS and Mac, since the Mac version won't play the Oggs, either.
Hmm.

Anyhoo..
Yippee, progress!! \o/yeay\o/