I'd say no, same casting, same spell. Plus it fits the spirit of Twin Spell since it is supposed to spread the damage out and not even Meteor Swarm gets to double up the damage through overlapping area.If the areas overlap and a creature is in the area of both spells is it affected twice, save twice, suffer damage twice?
It is not a separate instance.I'd say yes. Each is a separate instance of the spell with a different target.
And even if one tries to ignore the game developer, the ability says the same thing.KM @SymphFan
@mikemearls Does Twinned Spell make two spell instances (I.E., can't Concentrate on both spells) or change one spell instance to 2 targets?
Mike Mearls @mikemearls
@SymphFan One spell instance, two targets.
you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell