@Gilloo

I didn't try the usblist 68k binary included in the archive but compiled the source for OS4 instead. It didn't work because the OS4 interface test had the logic reversed.

I changed this:

if (IUSBSys != NULL)
{
printf("Cannot obtain USBSys interface\n");
CloseDevice( ioreq );
return 0;
}

to this:

if (IUSBSys == NULL)
{
printf("Cannot obtain USBSys interface\n");
CloseDevice( ioreq );
return 0;
}

and now it seems to work.

@Framiga
Early OS4 documentation stated that the OS4 68k emulator does not support 060 binaries and recommended the use of plain 020 versions of 68k software. I'm not sure if that's still true, but I would play it safe and use the 020 version.