Who saids can't avoid
The claim that the CPL skills test conduct prescribes deviating from track is utter rubbish.
Of course the candidate should demonstrate their ability to carry out the flight at minimum expense and time to the customer but NOT at the the cost of safety. Always - it will be legitimate to divert around weather when VMC is required to be maintained. The Minimum Altitude will be in accordance with the school SOP or Pilots Order Book. Should the SOP or POB require 1,000ft clearance above an obstruction then that must be achieved. If not, Rule 5 becomes the minima. The school approval will however require that a minima is clearly stated. Should minima not be achievable by diverting reasonably from track then the test should be terminated by the candidate. Should forcasts not have predicted the weather encounted it is not the fault of the candidate.