Correct. The only place it resides is in the System >> Administrative log. It has some decent info such as access, policy edits, group add/deletes but no very detailed.
I have a request coming from our risk auditor asking if SEPM has detailed logging on ch administrator anges, such as, someone schedules a change in the coming weekend, the change will update policy X with ABC modification, how will we know that is what ...
Please contact an admin to request access.