My policy of post post-editing is based a lot on your practice
Want to spend a few minutes polishing a post? Of course.
Editing a significant amount of time after posting is sort of suspect, mainly because, why bother? But it would depend on the change.
But Tech perfectly illustrated the poisonous potential of self-editing by changing the sense of his post 180 degrees. Which turned it into a kind of sneak attack on everybody who'd replied, especially those who got heated, who now might look like assholes to a casual observer. On a more abstract scale, it's an attack on the integrity of the conversational record...which is why the software has revision tracking and I don't have to consider the practice an existential threat to the Zone.
You handle the power responsibly, Tom. Techie didn't and lost it.