Уже получил ответ от разработчика ЮСБ-СПДИФ девайса:
"actually, I know of some users who connected hiFace to a normal USB 2.0 hub
with success. A device same as the one you indicate should be not much
different from a normal hub, so I think it`s usable. I`ve no tested it,
anyway."
Так что...