I'm skeptical. No matter how good the Phoenician sailors were, it seems unlikely to me that they could have blithely sailed past Cape Bojador[1] https://en.wikipedia.org/wiki/Cape_Bojador Maybe if they had small enough boats to stick close to the shore and portage. Seafaring on the Mediterranean is simply a lot less complex than it is on the open ocean. The European sailors were not able to pass this point till the 1…
Three correct details (Africa mostly surrounded by waters, Africa straddling the equator, Africa being very large) that would have been hard to make up out of sheer fantasy. Especially (2).
Though the Egyptians almost certainly long had known by then that the Earth is round and it's possible that he made very educated guesses and told us a fantasy just cause, and pretended to not believe the bit about the Sun just to make his story more mythical to his contemporaries. But is that likely? Did he do a lot of that?