I'd say the effects on say the Canaries and the Azores (though that may or may not be touched) would be absolutely huge, and the effects on Africa may be the same, with more Roman marine presence giving Rome more(compared to otl) trade with sub saharan Africa. The Africans would probably want Roman goods like sugar and the such in exchange sending Rome to gold and ivory and slaves.
Reasons:
1) India already had a pretty big sugar production during this time, if say Persia wanted it or something they could just buy it from India rather then Rome, and they'd face big competition, not what Rome would want.
2) Africa would be interacted more as coastal exploration increases looking for more areas like the Canaries, increasing Roman presence
3) Africa during this time was extremely isolated from the outside world and doesn't have things like sugar and advanced glassware as the Roman's have, basically giving Rome new markets to sell things as at a huge advantage, instead of just an endpoint wealth flowed out of.
Effects on greater history:
Rome would still fall around how it did as Romes biggest weakness was the decline in cities throughout the Empire, weakening it from the core. In fact Rome may fall slightly earlier with the slave society that would form in the periphery also contributing to the rot.
Africa would be more in touch with the rest of the world, and would be at least somewhat developed. That would in itself have huge effects and ripples as they could resist the Moors better.
Former Roman Africa and Sicily would probably still be Christian kingdoms, as the area would be richer and the Berbers in our timeline nearly repulsed the Arabs and this slight push in there favor may help them out here. That also means that they'd get the superior central Asian camel from the Arabs. With that they'd establish higher volume trade in Saharan Africa and they'd get absurdly wealthy from that, though being Christian they wouldn't ultimately make as much money as Christans during this age couldnt make the financial transactions the Muslims or Jews did.
Western Africa would probably be Christian by at least 1300, with Christians controlling the best trade routes and being the civilization the Berber armies and Romano/African traders would bring south, converting as they would go. Having other targets like Italy and Egypt it would likely be Morocco doing the heavy hitting in this, being the only direction they can really go.