Why You Should Download the Ultimate Edition of Batman v Superman
Those 31 minutes are not deleted scenes tacked onto the end. They are surgically inserted back into the narrative. Here is what those extra 31 minutes fix:
Direct Purchase
However, you can legally download the "better" version to own permanently. The law allows for personal backups of content you purchase, but the safest route is (Digital Rights Management or DRM-free where available).
Restored Narrative Logic:
Added scenes explain Lex Luthor’s complex framing of Superman in Africa and the Capitol bombing, making his "puppet master" role far more effective.