None that I'm aware of, but it'd be really easy to modify https://github.com/luphoria/reddit-migration (which I mentioned in https://kbin.social/m/RedditMigration/t/59451/Finally-Managed-to-erase-all-1477-of-my-comments ) to do it.
Here's a patch to the above with an untested change that should do what you want: https://kbin.social/m/DataDumps/t/83479/no-overwrite-patch
I fear you are giving too much credit to reddit though - 100% they won't care about the difference. If it nets them more money they will 100% undo the edit and leave only the original content there.