Sassanid Persia conquered Byzantine Egypt and then lost is a decade later. At the very least, a Sassanid military with the extra troops from an allied Himyar and/or Semien would make for a stronger conquest & hold. Their hold on Egypt might last longer than a decade. But that depends on who governs Egypt, the relationship between the Jewish kindom(s) and Persia, and how the Christian world reacts to all of that.Have doubts they could take Egypt, though like of the idea of Jewish Arabia / East Africa or network of Jewish states making significant gains in North Africa (amongst the Amazigh), Central Asia and South/Southeast Asia (in terms of followers at minimum if not quite states).
Oh and OTL there was a Jewish Berber warrior queen in Numidia. The spread of Judaism into north Africa is very plausible ITTL. I don't know about spreading farther into Asia, though. The Persian Empire in this scenario is still Zoroastrian and is certainly the dominant polity in the region. I see that spreading into central Asia much more easily than Judaism. Southeast Asia ... I dunno. I know basically nothing about the OTL spread of Islam into that part of the world. Or really very much about that part of the world at all