But it really works the other way around, though. It's a mass storage device, after all, and not a drive emulator.
As such, it never got any love at all from the demoscene, whence all people involved in the game hail.
So, SD2IEC ought to implement support for that loader.
I hear this hasn't been done in all these years mostly because the protocol kept changing constantly from one version to the next, evolving and improving.
However, it has now come to a point where i'm quite satisfied with it, finally, and i've also added some code to make supporting the loader including the relevant build-time options* as easy as possible.
So it might be that there won't be any protocol changes starting with (one of) the next version(s), paving the way for stable support by the SD2IEC firmware itself.
* An ID string is sent to the device prior to uploading the drive-side code. Currently it looks a bit like this:
idstring: .byte "u0", $18, ":krl", DIRTRACK, DIRTRACK81, FILENAME_MAXLENGTH