Elite 4, Champion, and post game = beat... I honestly think ScarVio in terms of story, even with its performance issues, is one of the best stories I've ever played, not just Pokémon either
It does during the story, but once the story is over, it's back to the regular game. It's just a matter of finding the Pokemon that only spawn down there. I found all of the Scarlet exclusives that only spawn there with relative ease.
