As scary as the damage output looks, it's not absurd. Since the boost is per hit and not per attack... you only really see a huge difference on single moves like Sunstone, f+2, standing 4, etc. The boost is completely lost on other specials like Sun Ray/God Ray, Sun God Choke (each hit gets a boost which ends up being around a total increase of 3%), and other multi hitting specials. Since it only makes you neutral and you have to work with whatever the frame difference is from the move you parried, it isn't braindead easy to capitalize on the damage.
It feels like they made the boost that way purposefully so they wouldn't need to patch it later. If someone's big recovery move gets parried and they take a boosted f+2 from it, they deserved it in the first place.