[Igelau]

> obviously the problem could be immediately "solved" with rm -rf .git && git init, but...

No buts about it. This is the way to go. That commit history is mostly junk. Its value is extremely limited and it's hanging around only because of fear and nostalgia. Archive it somewhere as read-only so that the worry warts will hush up and can reference when they need to (which IRL will be once or never), but just get rid of it in the live repo. The headaches you'll save yourself by starting fresh will vastly outweigh the problems you're afraid will happen.