I have never heard of Ozzy doing a Dio-era song live in Black Sabbath. IMO, some of their best material is on Heaven & Hell and The Mob Rules.
Has anyone in Black Sabbath ever said why they don't perform those songs live? Is it a "pride" thing for Ozzy? Is the material out of his vocal range? Or do they just only want to do 70s music with a few new songs peppered in?