Auditing remove note and persistent auditing.

In the auditing section, I can use the session event type filter and choose Added Note. I would like to have removed note as well. 

But while looking for a way to see if a note was removed I found that Audit logs are not persistent. For example.
Add a note, query the audit log and see that X machine has added a note.  Remove that same note then query the audit log and the event is missing, like I never added the note. 

Note auditing needs to be improved as we are using it for account control for SSO