Changing the USB VID/PID is only required for Apple Mac devices, which will flatly refuse to treat an iPod as anything but an iPod if it detects a known USB VID/PID combination.
I don't quite know what you're experiencing, but, this should absolutely not required for Windows hosts. Like, at all.
Additionally: who cares how old the Rockbox fallback version in emCORE is?
It exists for one reason, and one reason only. The facilitate an initial USB connection when Rockbox proper is not installed, or as an emergengy fallback. It has no codecs, no plugins, you can do absolutely nothing useful with it, other than use it for USB. The age of it is irrelevant, it does what it is supposed to.
Additionally (take 2): are you aware that the thread you link to is absolutely and totally irrelevant for the iPod 6G? That's an ancient thread (2007) for the iPod 5G (Video), from before we had reliable USB. And even that has nothing to do with the USB VID/PID at all. I'm confused. There's been a couple of times now when you seem to have confused iPod Video and iPod Classic (now, and in your sources), these devices have very little in common, and absolutely nothing in common relevant to USB.