Idea behind “Your vote is now locked in unless this answer is edited”
I fail to see the reasoning behind not allowing me to change my mind on an answer.
Here's my situation: I read the answer, saw that it was suggesting something that I considered not ideal and so downvoted the answer. After further research I realized what I had originally considered the ideal solution was in fact not possible, thus I decided to remove my downvote on the question.
To my surprise, Stack Overflow in all its supreme-overlordliness wouldn't let me undo my downvote, presumably because my chance to change my mind had expired!