I understand that undoing a downvote after the grace-period is denied for strategic reasons (explained here: Unable to undo downvote).
But what if your downvote was just an accident which you did not notice right away? I'd like to make up for my bad vote and I do not care about the points.
Would it be possible to allow an upvote to compensate for the downvote but without regaining the reputation points spent for downvoting?
EDIT: Sorry for the confusion. I was just talking about voting on answers.
Okay, the real reason for vote locking may be another than I assumed, but it does not matter for this discussion: What negative consequences are to be expected, if upvoting (for compensating accidentical, locked downvotes) was allowed? (The upvote would of course get locked, too.)