Where was Damian?

It occurs to me that the late sixth century, when Egypt's Copts seceded from Orthodoxy as prelude to them signing on with the Sasanians... was also the heyday of the Nubian kingdom "Nobadia". I read Obłuski's book, it was great. I also note it's six/seven years later. How tempus fugit. Sooo...

In the late sixth century, "Orthodoxy" and "Catholicism" were about the same. The Latin Church was pulling toward a Dyothelete model under Augustine's influence. The Greek Church also had her dyotheletes, like John Chrysostom and the now-underrated Epiphanios; and by then the Syrians across the Euphrates were claiming to be full "Nestorians", although at this point there was some nuance here as among the Greeks.

Among the Greek Orthodox Parents were Gregory and Macrina of Nyssa, who condemned slavery. The Latin Church never was much for that peculiar institution; but it did make compromises thereto, especially after the (Latin-speaking) Portuguese drove down the slave-trade's costs. I understand that Justinian's Law imposed some restrictions, as well.

Not so much the Sasanians. They'd found that Khuzestan and lower Iraq were both fine places to grow sugar-cane; to work them, they hit the Zanj south of the Somali coast. The Sasanian ideology was an Iranian one (to be polite) which saw the Aniran as intrinsically inferior. ("Chionan" is that part of Aniran they couldn't control.) If they could find Aniranians who could grind down Chion for them, that was the sweet spot. As it were.

Where sugar grows, cotton also can grow. That's another cash crop - even absent a Cotton Gin. This plant doesn't just grow along the Persian Gulf. It also grows in Egypt.

So I have to ask, how did Egypt get the cash-flow to support TWO church hierarchies, one Greek and one Coptic? I have a suspicion: Egypt became more profitable because of cash-crops, which weren't worked by native Egyptians, neither Greek nor Coptic. Nobadia was a slave state; its signature archaeologic feature, as Obłuski documented, was the slave pen.

I haven't asked what Popes Damian and Peter IV wrote about how, exactly, their new church was getting funded. Will Copts like the answer?