I apologize if this has been brought up, but in the last several days I have not seen anyone address this specific topic from Across the Sea.
I re-watched Across the Sea last night and caught a connection that I previously missed.
When Mother gives Jacob the wine, he says that he does not want to take on the responsibility of protecting the island. Mother says to him, "you don't have a choice."
I thought this was a really nice way of contrasting how Jacob's views differ from those of Mother (and from those of MIB).
When Ben is getting ready to kill Jacob, Jacob says "I want you to understand one thing: you have a choice." Jacob clearly believes in the necessity for everyone to have a free will choice. Jacob believes that man can be good, and that they can be good by making free-will choices. This is a direct contrast to Mother's belief (which MIB came to agree with) that man is evil and cannot be trusted to make free-will choices.
Like I said, I completely missed this during the first watch-through, but the second time I watched Across the Sea, I found Mother's comment to be a powerful contrast to what Jacob says to Ben. I think this will also play into the passing of the responsibility to the next Candidate. Jacob will want the next protector to take his place by making a free-will choice, rather than having the responsibility forced on them as it was with him.