I don't think the concern was necessarily about overhead, but about sensitive data. This is a problem in Git too: people make the mistake of reverting a commit with sensitive values and think it's gone, but the history is still out there.
Edit: or maybe that was the concern, but this other concern exists too :)
If thats what you're worried about, use Yjs. Yjs doesn't store deleted characters in documents. Unless you actively make yjs snapshots, once a character in a yjs document is deleted, its gone.
Edit: or maybe that was the concern, but this other concern exists too :)