Is the Discovery Pass worth it if I only plan to visit two attractions?

No, you’re almost certainly better off paying separately. These passes are designed around the assumption you’ll hit three, four, or five spots in a short window, and the math only works in your favor if you actually use that volume. For two attractions, you’re paying for optionality and convenience you don’t need, and probably losing money on the deal. Save the pass for a trip where you actually plan to use it.