As an example, one of the planned stops on my test was to a dirt strip without a navaid
You are quite entitled to advise your testing officer (ATO or FOI) that what he is asking is NOT a CASA requirement for an IRT and that you will refuse to conduct this exercise. Moreover you should report him to his regional manager for exceeding his authority.
The so called "no-aid" leg was a common feature of CIR tests conducted in the Vic/Tas region of CASA even though the CASA Form 645 Instrument Rating Application did not have a requirement for this sequence. A complaint was made to CASA head Office Canberra who quite correctly advised that a "no-aid" testing requirement was not CASA policy.