Some small operators do have an in house check and training system and therefor subregulation 2 would apply.
If this is not the case then you can't do any training and/or checking without an instructor rating/examiner rating or other similar approval from CASA.
Nothing stops someone sitting in the right seat as an observer/passenger though. That person just cannot log any flight time and is at the mercy of the actual PIC in the left seat.
My suggestion would be that operator apply for an in house check and training approval.