Spiffo
I agree, I ultimately tend to treat them both as being simultaneously in both places in some way. It works especially well if we assume the double loop to be a Moebius.
Without wanting to appear elitist; individuals evolve at different rates. I get that AC was happily living in the Aeon of Horus, with occasional forays back into the Aeon of Osiris, if the more outrageous tales are to contain at least a kernel of truth. I also get that the Aeon of Osiris follows the Aeon of Isis, and in turn gives way to the Aeon of Horus (hurrah, because that's a cool Aeon). So I figure the transition between Aeons is not like an on/off switch, it's gradual, with peaks and troughs, of influence, during the transition. I feel in my own self deep stirrings of Horus-ian Will and yet have to function in a world of (seemingly) Osiris-ian energy and materiality. Bugger.
Anyway, that's how I see the whole Emperor/Star thing playing out. In meditations with those cards, and their duel roles, if you will, I've found being able to use them in both attributive-forms, that their purpose and power is enhanced. I even dare to wonder if this is not exactly what AC intended. ⊕