I think the last one would be sufficient in most cases and 'all of them' would be difficult. However...if the box could hold a sufficiently long reason, the edit page could show "edit info to date" and give you something to click to toss it into the edit reason, and then you could add on to it? Still...bleh. I'm not sure that's a good idea. I think at least an optional edit reason box (storing just the most recent) would be good tho.