I was about to suggest this, but I saw it was asked.
I have a solution, **please hear me out**:
I have had this problem many times: I have posted a wall post and then needed to change a part of it, so I copy it, delete it, and then edit the part. But then I see another mistake in typing, so I do this over again. I do this until I run out of wall posts, and cannot post the one I wanted to. I know the limited wall messages setting is to prevent spam, and I know lack of editing is so no one can avoid ban, however...
I want a sort-of **temporary** wall post editing. After you post a wall message, there is a short time you can delete it when it isn't on your wall. Make it editable during that period as well. After the period, the post can't delete or edit. Mods and editors can view previous edits. This way, you don't have to waste as much wall posts to get a message across when you make a mistake. Because we all make mistakes, Right?
So, is this considerable now? (*Yes, I know this is very well a minor suggestion*)
##So this is essentially a bump and reasoning.
Please don't hate :(
Hope I helped! (As always) :P