The Example above shows examples of using [AutoPopulate] to populate audit fields, there’s also support for Executable Crud Audit Events with the new OrmLiteCrudEvents provider which gives you an executable audit history for your AutoCrud Services for essentially no effort.
If you need to save related fields, then you can’t use AutoCrud and would need to create your own custom implementation at which point you would populate the audit fields yourself. There shouldn’t be any reflection or filters used as your custom implementation would be populating the Audit fields of the concrete types and saving them directly. I also don’t see why you’d use reflection to populate your own Audit fields, you know what the structure of your audit fields are, so have your tables that contain them implement the same interface.