Atlassian documents changedFrom / changedTo on audit records, but the only example in the docs is a user-management email change. I haven't been able to confirm from documentation whether those fields populate for configuration events — a permission scheme edit, a workflow change, a custom field context change.
If you're on Standard or above and have a minute: change something small in a permission scheme, then pull GET /rest/api/3/auditing/record and look at changedValues on that record. Is it populated, empty, or absent?
I'm asking because the answer decides whether the audit log can tell you what a change contained, or only that one happened. Those are very different things if you ever have to reconstruct a change weeks later.
I work on tooling in this area, so I have a dog in this fight — but I genuinely can't find this documented anywhere, and I'd rather know than assume.