Allow manual override for edits

Question

I'm often incredibly annoyed by this message*:

Oops! Your edit could not be submitted because:
This post has already been edited. Your edit must be more substantiative to override the current edit.

Every single time this message has appeared for me, my edit has, in fact, been more substantiative. So I copy the text of the body out into Notepad along with the title, refresh the page, and put my edit in again. It's completely pointless. I can see four solutions to this problem:

1. Pop up a notification when Save Edit is clicked, but with the option to save anyway. The editor can then look back at the history and check which edit was better, then roll back if the later edit wasn't as good as the earlier one.
2. Pop up a notification when Save Edit is clicked that another edit has been made, and show the other edit that was made in a side-by-side diff with the current edit, where the editor can then merge the changes.
3. Improve the diff algorithm. I'm really not sure how it can't tell that my edits are more substantiative, given that looking at the diff afterwards obviously shows only improvements...
4. Live, collaborative editing! If someone is already editing, do Google-Docs-style collaboration.

I realize that #4 isn't really realistic, but it would still be awesome :)

_{* That might not be the exact message. I can't remember.}

Answer 1

I particularly like option 2 as it allows for merging.

Often in the suggested edit review one of two things will happen:

You take the time to improve an edit and you get the message that it has already been approved and have to go to the post directly and edit it from there.
See The robo-approvers are killing my will to review edits

Or

Multiple improvements are performed at the same time, and inevitably if you’re taking your time and try to do a good job someone will beat you to the punch.

In the latter case allowing for merging would be a great solution, the other editor while faster may have caught something I missed, or while I was taking my time I may have caught something that he or she missed. Either way giving the option to see both edits side by side and possibly merge them makes for a much more thorough and collaborative process.