On Stack Overflow, when you edit a post within 5 minutes of your last edit and nobody edited the post in the meantime, the edits are merged into one. This way, if you find a mistake in your edit, or if you quickly find something else to change after the edit, only one edit will be visible.
I think having full revision history is much more important in MediaWiki than on SO, but something like this could be useful anyway. Maybe something like keeping the default the same, but adding an option to edit the last edit could make sense.
(I would be surprised if a feature like this wasn't suggested before, but I didn't find it here.)
Version: 1.22.0
Severity: enhancement