Got a custom entity which has auditing enabled. Every time an user changes the stage on the Business process flow (BPF) on that entity, it's generating an audit log record with the change in the stageid which is irrelevant for the business and i cannot use the modifiedon field since the stage change is changing the modifiedon field data as well, which makes the data irrelevant for the business.
One idea would be to create a field called Business Data Modified On. Then, create a workflow that runs on change of the fields you consider to be business data and have the workflow set the new field to the current time.
It does not appear that Auditing can be disabled on the managed field StageId.