Theoretically the patriarch of Alexandria is responsible for Carthage right? What's the Orthodox population looking like there these days? I believe it's still a rather small exclave.
Related thought, I wonder if we might see the patriarch of Alexandria funding or pushing for any kind of colonization/proselytization in Africa to expand his influence. I could definitely see the Romans being able to support a colony on something like Zanzibar or Madagascar. I know we've had some conversations about the topic of African colonization, but it's been a very long time and I can't remember where people landed.
It would be interesting to see if the Romans controlled Zanzibar - no idea who does at the moment, but I doubt it's uncontrolled. Its a great place for Roman protectorates, or Romano-Ethiopian protectorates in reality (given Ethiopian proximity).
Plus it might allow the Romans to benefit (slightly) from the Cape trade route that undermines the Red Sea trade (or a good base to attack it from during wartime).
Tbh, I'd love to see a native Swahili state dominating East Africa and aligned with the Romans. Not something I've seen in a lot of timelines, but it could be really interesting. It would be interesting to look at that region, since even historically it was involved in trade with China as a resource exporter, and whilst we've had a lot of focus on East Asia, and its place in the trade, East Africa would be a new bit for the story. It also could be interesting with its ties to India, as the big V might have something to say about any Europeans there. Sadly it might also be a new target for the Triunes, since they lost the Bengal.