back to the original topic, what exactly is the reason you only have 30 minutes to edit a post?
Moderators check all new posts. Moderators will delete non conforming text to adjust the post to the rules.. such as, email addresses, pricing or competitive links to maintain the integrity of the post the majority of the time.
If a Moderator changes the post to conform to the rules then the OP can and will, I might add change, it back. This is why we only allow a few minutes for the OP to edit his post.
All the Moderators are volunteers. It's time consuming enough to stand watch but to have to go back and preform his duties twice is uncalled for. Also, if the OP changes a Moderators ruling then he is subject to a punishment deemed appropriate by the Moderating staff.
IF the OP would like his post edited after the time allowed he may simply hit the report post button and ask that a Moderator edit it for him.