Well, as it is the mods on this forum are challenged to handle the number of reports when posters object to reactions other members have made to their posts. “Self-policing” can too easily go over the line with respect to the courtesy guidelines of the Terms of Service. Of course, some members would handle this well, but for others it could lead to more inflammatory exchanges. Again, we have to balance the desire for flexibility with the demands of moderation. Please keep in mind that our community is huge compared to many other forums.
Also, if posters wish to change what they have said after the 20-minute period, they can always make a subsequent post to clarify or revise their comments. It is just that the original comments will remain. Again, don’t post what you do not want out there.