Most discussion that ensues on the voting of some members would only happen (if it happened) after results were published. While it may not appear, some discussions may actually be a bias to future members who are yet to vote and may feel constrained in voting in a specific user after seeing the feedback that the overall community has whenever that user is mentioned in a certain category.
The opposite can also happen: I wouldn't have thought of everyone I voted for without being reminded of their names by someone else.
The PM would be considered a final vote and there wouldn't be room for edits/changes (it would depend on the rules established by whoever was running the event however).
Or a second PM would replace the first one.
I think it's achievable to code a (python?) bot to scrap PM's, look for certain aspects (subject, see if member fills contest/event criteria, if the body is according to the format of entries, ...)
In my experience, many people won't follow the correct format.
I've increased the update frequency from every 2 hours to every 5 minutes.